The Jean Monnet Program

Professor J.H.H. Weiler
European Union Jean Monnet Chair

Jean Monnet Working Paper 1/02

Joost Pauwelyn

THE NATURE OF WTO OBLIGATIONS

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ISSN 1087-2221
 Joost Pauwelyn 2002
New York University School of Law
New York, NY 10012 
USA
THE NATURE OF WTO OBLIGATIONS

Joost Pauwelyn

This paper offers two propositions.  Firstly, WTO obligations are bilateral/reciprocal in nature.  They are not of the multilateral, integral or erga omnes partes type (Section I).  Secondly, WTO obligations are of a continuing nature.  They cannot be equated to an expression of state consent limited to 15 April 1994, the date of conclusion of the Marrakesh Agreement (Section II).

The WTO Agreement is, obviously, a multilateral agreement.  It will soon have 144 signatories.  But what is the nature of WTO obligations?  Are they of the bilateral (or reciprocal) type, in that WTO obligations can be reduced to a compilation of bilateral treaty relations, each of them detachable one from the other.  Or are they of the multilateral (erga omnes partes or integral) type, in the sense that their binding effect is collective and the different relationships between WTO members cannot be separated into bilateral components?  This is the first question that this paper tries to answer.  Classifying WTO obligations in either of those two categories has major legal consequences:  Firstly, for the permissibility of inter se modifications to the WTO Agreement.  Secondly, in terms of the acceptability of suspension of WTO obligations in response to breach.  Thirdly, for the rules on standing to bring a complaint before a WTO panel.  Generally speaking, in case WTO obligations were of the multilateral type, inter se modifications to the WTO treaty and the suspension of WTO obligations as against a wrongdoing state would not be acceptable, whereas standing to bring a WTO complaint would be granted to all WTO members, irrespective of the breach.  In contrast, if WTO obligations were seen as bilateral obligations, inter se modifications and suspension in response to breach would be permissible, whereas standing would be limited to only those WTO members at the other end of the (compilation of) bilateral relationship(s) allegedly breached.  

The second issue addressed in this paper is whether it is feasible to put a fixed time-label on the WTO treaty.  This is important, firstly, for the interpretation of WTO provisions.  Should they be interpreted with reference to intentions and law contemporary with the formal conclusion of the WTO treaty, or in an evolutionary manner taking account of new developments at the time of application?  The issue of timing is crucial also when WTO provisions are in conflict with other rules of international law and the question arises as to which of these two norms is later in time, i.e., the lex posterior which, in principle, prevails.  For purposes of applying the lex posterior rule to WTO obligations, is 15 April 1994 really the critical date or should one rather consider the WTO treaty as a regulatory instrument which evolves and is continuously monitored, confirmed and re-concluded in the context of an international organisation?  If the latter were true, a proposition defended here, in case of conflict between WTO provisions and other what I term “continuing” norms (such as, arguably, a number of multilateral environmental or human rights treaties), there would no longer be “successive treaties”, but rather “parallel treaties”.  As a result, the lex posterior principle would not apply in the first place.  Rather, the conflict ought then be resolved by means of other tools, in particular the lex specialis rule pursuant to which the more specific norm prevails over the more general one.  

Both questions examined in this paper are crucial for the relationship and hierarchy between WTO law and other norms of international law.  More profoundly, taking sides on these questions offers a prominent yardstick when setting out the WTO’s object and underlying purpose as well as its place in the wider context of other, non-trade-related aspects of international relations. 

I.	WTO OBLIGATIONS ARE BILATERAL OBLIGATIONS

A.	Background of the distinction between bilateral and multilateral obligations

The distinction between bilateral (reciprocal) and multilateral (integral) obligations cannot, in so many words, be found in any codified rule of international law.  Nonetheless, it has major consequences and is reflected in a number of norms on the law of treaties and state responsibility.  

1.	Early PCIJ and ICJ cases
In the Reservations to the Genocide Convention case (1951), the ICJ gave particular importance to the “objects” of the Convention.  It noted that “[t]he Convention was manifestly adopted for a purely humanitarian and civilizing purpose.  It is indeed difficult to imagine a convention that might have this dual character to a greater degree, since its object on the one hand is to safeguard the very existence of certain human groups and on the other to confirm and endorse the most elementary principles of morality”.  With reference to these “objects”, the ICJ lay the foundation of what was to become the distinction between reciprocal and integral obligations:  

“In such a Convention [as the Genocide Convention] the contracting States do not have any interests of their own; they merely have, one and all, a common interest, namely, the accomplishment of those high purposes which are the raison d’être of the convention.  Consequently, in a convention of this type one cannot speak of individual advantages to States, or of the maintenance of a perfect contractual balance between rights and duties.  The high ideals which inspired the Convention provide, by virtue of the common will of the parties, the foundation and measure of all its provisions”.  

It was with reference, inter alia, to these “objects” that the Court made its main finding:  “The object and purpose of the Convention thus limit both the freedom of making reservations and that of objecting to them.  It follows that it is the compatibility of a reservation with the object and purpose of the Convention that must furnish the criterion for the attitude of a State in making the reservation on accession as well as for the appraisal by a State in objecting to the reservation”.  The ICJ’s approach to treaty reservations was incorporated subsequently in Art. 19(c) of the VCLT, prohibiting reservations to a treaty that are “incompatible with the object and purpose of the treaty”. 

In earlier opinions by individual PCIJ judges, other hints at a distinction between reciprocal and integral treaties were made.  In the Customs Régime Between Germany and Austria case, Judge Anzilotti questioned whether the parties to the 1922 Geneva Protocol 

“were in a position to modify inter se the provisions of Article 88 [of the Treaty of Saint-Germain], which provisions … form an essential part of the peace settlement and were adopted not in the interests of any given State, but in the higher interest of the European political system and with a view to the maintenance of peace”.

Another reference can be found in the dissenting opinions of judges Van Eysinga and Schücking in the Oscar Chinn case.  In contrast to the majority of the PCIJ, judges Van Eysinga and Schücking expressed the view that the 1919 Convention of St. Germain relating to the Congo Basin was void between its signatories on the ground that it modified the earlier General Act of Berlin of 1885 without the assent of all the signatories thereto.  Judge Van Eysinga expressed it thus:  

“the Berlin Act presents a case in which a large number of States, which were territorially or otherwise interested in a vast region, endowed it [the Congo Basin] with a highly internationalized statute, or rather a constitution established by treaty, by means of which the interests of peace, those of ‘all nations’ as well as those of natives, appeared to be most satisfactory guaranteed … [It] does not create a number of contractual relations between a number of States, relations which may be replaced as regards some of these States by other contractual relations … This régime, which forms an indivisible whole, may be modified, but for this agreement of all contracting Powers is required”.  

2.	The ILC Reports on the Law of Treaties by Sir Gerald Fitzmaurice 
Fitzmaurice refined the distinction between treaties referred to in the previous section and re-phrased it as one between “reciprocal” or “concessionary” obligations, on the one hand, and “integral” obligations, on the other.  Multilateral treaties of the “reciprocating type” are those “providing for a mutual interchange of benefits between the parties, with rights and obligations for each involving specific treatment at the hands of and towards each of the others individually”.  Whereas multilateral treaties of the “integral type” are those “where the force of the obligation is self-existent, absolute and inherent for each party”.  In other words, “integral obligations” are those “towards all the world rather than towards particular parties” and “do not lend themselves to differential application, but must be applied integrally”.  

The standard example given by Fitzmaurice of a treaty of the reciprocating type was the 1961 Vienna Convention on Diplomatic Relations; that of the integral type, the 1948 Genocide Convention.  

Fitzmaurice attached two important legal consequences to this distinction, one in the field of termination/suspension of treaties, the other in the field of conflict between treaties.  Treaties of the reciprocating type could, in Fitzmaurice’s view, be suspended or terminated as a result of fundamental breach.  Moreover, later treaties conflicting with previous ones of the reciprocal type were, in his view, not null and void (instead, priority rules applied).  Integral treaties, in contrast, could, under Fitzmaurice’s draft, not be terminated or suspended by the other parties as a result of breach (“the juridical force of the obligation is inherent, and not dependent on a corresponding performance by the other parties to the treaty”).  In addition, any subsequent treaty concluded inter se by the parties to such integral treaty which “conflicts directly in a material particular with the earlier [integral] treaty will, to the extent of the conflict, be null and void”.  

Fitzmaurice also added a third type of multilateral treaties, namely those of an “interdependent nature”, where “the participation of all the parties is a condition of the obligatory force of the treaty”.  He gave treaties on disarmament as an example of interdependent treaties.  In terms of termination/suspension as a result of breach, interdependent treaties could, in Fitzmaurice’s view, be terminated in their entirety by the other parties in case of fundamental breach (not just suspended or terminated partly as was the case for reciprocal treaties), since for these treaties “performance by any party is necessarily dependent on an equal or corresponding performance by all the other parties”.  However, much like “integral treaties” (and unlike “reciprocal treaties”), a later inter se treaty which “conflicts directly in a material particular with the earlier [interdependent] treaty will, to the extent of the conflict, be null and void”.  This notion of “interdependent treaties” will not be further referred to here.  Unlike the notions of reciprocal and integral treaties, the concept of interdependent treaties has not been generally used as a distinct category subsequently to Fitzmaurice’s reports.  For purposes of conflict of norms (essentially, the legality of inter se modifications), these interdependent treaties can, indeed, be equated with integral treaties.

3.	The Vienna Convention on the Law of Treaties
Fitzmaurice’s distinction between reciprocal, integral and interdependent treaties was not maintained in the Vienna Convention as it was finally concluded.  Nonetheless, it left its traces in not less than six different provisions.  The Convention deals with termination/suspension as a result of “material breach” in its Art. 60 and conflict with earlier treaties in its Arts. 30, 41, 53, 58 and 64.  

Firstly, under Art. 60.5 termination/suspension as a result of material breach is not allowed in case of “provisions relating to the protection of the human person contained in treaties of a humanitarian character, in particular provisions prohibiting any form of reprisals against persons protected by such treaties”.  These treaties can, indeed, be seen as an example of integral treaties in respect of which Fitzmaurice precluded termination and suspension (although not all integral treaties have been kept outside the scope of Art. 60, contrary to what Fitzmaurice originally proposed).  Secondly, Art. 60.2(c) allows any other party (not just the party specially affected by the breach) to suspend the treaty, in whole or in part, with respect to itself “if the treaty is of such a character that a material breach of its provisions by one party radically changes the position of every party with respect to the further performance of its obligations under the treaty”.  This provision resembles what Fitzmaurice wanted to see in respect of interdependent treaties (e.g., disarmament treaties).  Thirdly and fourthly, the reference in Arts. 53 and 64 to “peremptory norms”, conflict with which invalidates other treaties, is reminiscent of Fitzmaurice proposal to invalidate treaties in conflict with any treaty of an integral or interdependent nature.  However, Arts. 53 and 64 do not cover all conflicts with integral treaties, only conflicts with integral treaties of a particular type, namely those of jus cogens.  Fifthly and sixthly, Arts. 41 and 58 recalls Fitzmaurice proposal to invalidate inter se agreements in conflict with integral or interdependent treaties, when it outlaws (though not invalidates) inter se modifications to a multilateral treaty that “affect the enjoyment by the other parties of their rights under the treaty or the performance of their obligations” or relates to “a provision, derogation from which is incompatible with the effective execution of the object and purpose of the treaty as whole” (Art. 40.1(b)(i) and (ii)).  Art. 58 provides for similar rules in respect of the inter se suspension of multilateral treaties.     

4.	The ILC Draft Articles on State Responsibility 
Much aligned along Fitzmaurice’s distinction between reciprocal and integral/interdependent obligations, James Crawford in his Third Report to the ILC on state responsibility distinguishes between “bilateral” obligations and “multilateral” obligations.  In his view, “bilateral obligations can arise from a variety of sources, including general international law, bilateral or multilateral treaties or unilateral acts”.  Crawford, like Fitzmaurice, refers to the Vienna Convention on Diplomatic relations as an example of a multilateral treaty setting out legal relations that are essentially bilateral in character. As opposed to bilateral obligations, Crawford posits the notion of multilateral obligations.  Such multilateral obligations are subdivided into two classes.  

Firstly, multilateral obligations of the erga omnes type, “owed to the international community as a whole, with the consequence that all States in the world have a legal interest in the compliance with the obligation”.  This is the type of obligation erga omnes referred to by the ICJ in the Barcelona Traction case, itself distinguishing between reciprocal/bilateral obligations and integral/erga omnes obligations taking diplomatic relations as the standard example of the former type of obligations:  

“an essential distinction should be drawn between the obligations of a State towards the international community as a whole, and those arising vis-à-vis another State in the field of diplomatic protection.  By their very nature the former are the concern of all States”.  

Erga omnes obligations are, in Crawford’s view, “virtually coexistensive with peremptory obligations (arising under norms of jus cogens)”.  

In the Final Draft Articles, adopted in August 2001, multilateral obligations of the erga omnes type are referred to as obligations “owed to the international community as a whole”.  The Commentary to the Final Draft Articles states that it is not its function to provide a list of those obligations.  It refers instead to (i) the Barcelona Traction case which it gave the following examples: “the outlawing of acts of aggression, and of
Genocide” and “the principles and rules concerning the basic rights of the human person, including protection from slavery and racial discrimination”, and (ii) the East Timor case, where the ICJ added the right of self-determination of peoples to this list. 

The second class of multilateral obligations identified in the ILC’s work on state responsibility are those owed erga omnes partes, i.e., owed, not to all states, but to all the parties to a particular regime (e.g., a multilateral treaty).  In Crawford’s view, this class concerns “obligations which are expressed (or necessarily implied) to relate to matters of the common interest of the parties”.  In other words, the performance of the obligations of each and every state party is recognised as being in the common interest of all state parties, common interest being defined as an interest “over and above any individual interest that may exist in a given case”.  As examples he refers to obligations that arise “in the fields of the environment (for example, in relation to biodiversity or global warming) and disarmament (for example, a regional nuclear free zone treaty or a test ban treaty)”.  Elsewhere Crawford rightly points out that “human rights obligations are not the only class of international obligations whose performance cannot be considered as affecting any ‘particular State’ considered alone.  This is also true of some obligations in such fields as human development, world heritage and environmental protection”. 

In the Final Draft Articles, multilateral obligations of the erga omnes partes type are referred to as obligations “owed to a group of States … and … established for the protection of a collective interest of the group”. Pursuant to the Commentary to the Final Draft Articles, multilateral obligations erga omnes partes 

“must apply between a group of States and have been established in some collective interest.  They might concern, for example, the environment or security of a region (e.g. a regional nuclear free zone treaty or a regional system for the protection of human rights).  They are not limited to arrangements established only in the interest of the member States but would extend to agreements established by a group of States in some wider common interest”.

The Commentary explicitly states that it is not its function to provide an enumeration of collective interests giving rise to multilateral obligations erga omnes aprtes.  It states, though, that “their principal purpose will be to foster a common interest, over and above any interests of the States concerned individually”.

The distinction between bilateral and multilateral obligations (in particular those of the erga omnes partes type) may not always be easily discerned.  The Commentary to the Final Draft Articles states that “[i]t will be a matter for the interpretation and application of the primary rule to determine into which of the categories an obligation comes” and stresses that it only offers an “illustrative” discussion. 

The consequences attached to the distinction between bilateral and multilateral obligations in the Final Draft Articles relate to the question of standing.  Legal standing to invoke responsibility for breach of a bilateral obligation is limited to the state at the other end of the bilateral relationship (that is, the “injured State”).  Breach of a multilateral obligation, in contrast, can be invoked either (i) by each and every one of the other parties to the multilateral treaty, in case of multilateral obligations erga omnes partes, or (ii) by any state, in case of obligations erga omnes, that is, binding on all states of the international community.  For breach of multilateral obligations, two types of standing are, however, introduced.  Only those states that are “specially affected” by the breach (so-called “injured States”) are granted full standing, that is, standing to claim all of the remedies related to breach (cessation, non-repetition, reparation and countermeasures).  All other, not “specially affected” (i.e., not “injured”) states party to, or bound by, the multilateral obligation have standing only to claim cessation of the wrongful act and assurances and guarantees of non-repetition in the collective interest.  They can also claim reparation, but only in the interest of the “injured State”.  The Commentary to the Final Draft Articles leaves it open as to whether these “non-injured” states can impose countermeasures.  In any event, for those states to impose countermeasures, if at all possible, will be more difficult than for “injured States”.

5.	What the distinction is not about
First of all, the problem of identifying whether an obligation is of a bilateral/reciprocal or multilateral/integral nature is not linked to the source of the obligation concerned.  It is, in particular, not sufficient that an obligation derives from a multilateral treaty, for that obligation to be of the multilateral type (e.g., for all parties to that treaty to have standing to invoke breach of the treaty).  The very question at issue is to distinguish between different types of obligations all of which derive from a multilateral treaty.  Hence, the fact that WTO rules derive from a multilateral treaty is not enough for WTO obligations to be of the integral type. 

Secondly, the notion of multilateral/integral obligations should not be equated with obligations that are binding on states without their consent.  Some integral obligations are binding on all states, irrespective of their consent, namely obligations deriving from norms of jus cogens.  However, most integral obligations (such as those in the field of environmental protection) are binding only erga omnes partes, i.e., binding only on the states party to the treaty. 

Thirdly, to say that obligations are reciprocal in nature does not necessarily mean that they are affecting only two governments in their bilateral relations.  They may well affect also individuals or economic operators other than public authorities.  The fact that obligations have a direct or indirect effect on individuals does not make them integral (although most integral obligations, being obligations "in the collective interest" will have a beneficial effect on individuals also).  As clarified below, WTO rules are a perfect example of rules of a mainly reciprocal type that nonetheless have a clear effect on individual economic operators.

Fourthly, obligations of the reciprocal type should not be confused with obligations performance of which is inherently conditional on reciprocity.  Although reciprocal in nature, reciprocal obligations may well be (and mostly are) unconditional, objective and self-existent in the sense that they must be complied with irrespective of compliance by other state parties (unless, of course, non-performance is justified as a suspension under Art. 60 or as a countermeasure).  Here again, WTO rules are a perfect example.  The WTO obligation to accord most-favoured-nation (MFN) treatment is an unconditional one:  A WTO member must grant MFN status to imports of all other WTO members irrespective of how these other WTO members treat its own exports.  MFN is, in that sense, not conditional on reciprocity.  Nonetheless, although certain breaches of the MFN obligation may well affect all other WTO members, the MFN obligation is not as such an obligation of the multilateral/integral type.  A breach of the MFN principle does not necessarily affect the rights of all WTO members (the discrimination may well be targeted at only one state).  Rather, MFN is essentially a collection of equivalent bilateral legal relationships in respect of which no discrimination is allowed to take place.  It is, in other words, an obligation of the bilateral/reciprocal type.

B.	Why are WTO obligations bilateral obligations? 

1.	A tentative general criterion to make the distinction and its application to WTO obligations
In Section A above, we set out the background and multiple legal consequences of the distinction between bilateral/reciprocal obligations and multilateral/integral obligations.  It is time now to suggest a general criterion to make this distinction, knowing that the specifics of provisions dealing with particular consequences related to the distinction differ. 

Reciprocal obligations are those where the legal matrix can be limited to a bilateral relationship between two states.  Even if the obligation derives from a multilateral treaty binding on a large number of states, such reciprocal obligations can always be reduced to a compilation of bilateral state-to-state relationships.  Hence, to affect or alter one of these bilateral relationships does not normally impunge on the other bilateral relationships, each of these relationships being detachable one from the other.  Consequently, bilateral suspension or modification of reciprocal obligations is permissible and their breach can only be invoked by the state(s) at the other end of the bilateral relationship(s).  The binding effect of integral obligations, on the other hand, is collective in nature.  The different relationships between states bound by an integral obligation cannot be separated or detached into bilateral components.  Hence, to affect or alter an integral norm will necessarily have an impact on all states bound by that norm.  It cannot be limited to the bilateral relationship between two states.  Consequently, bilateral suspension or modification of integral obligations is not permissible and their breach can be invoked by all states to which the obligation is owed.
 
In sum, the central question is the following:  Does breach of the obligation in question necessarily affect the rights or obligations of all other states bound by the rule concerned?  If so, the obligation is of the multilateral/integral type.  If breach may affect the rights or obligations of only one, more or sometimes all other state parties, then it is of the bilateral/reciprocal type.  This criterion shows that it is impossible to define a treaty in its entirety as reciprocal or integral in nature.  One must look at every provision and every obligation individually.

Under this criterion, WTO obligations are of the reciprocal type.  They are not integral in nature.  A breach of WTO obligations does not necessarily affect the rights of all other WTO members.  More than one, and in some instances all, WTO members may be so affected.  But if all WTO Members are, indeed, affected this is not necessarily so, based on the nature of the WTO obligation.  It is a consequence rather of WTO obligations being trade-related and trade restrictions, in turn, being capable of affecting the economic interests (not necessarily the rights) of many WTO members.  That WTO obligations remain reciprocal and are not integral is, however, not always clearly discerned.  The one author who, to my knowledge, examined this issue came to the same conclusion as I do here.  Michael Hahn, after considering the hypothesis that GATT obligations are to be fulfilled erga omnes partes (and could, hence, be qualified as integral) reaches the conclusion that the basic structure of these obligations is against such qualification.  He as well is of the view that both GATT and the WTO treaty remain treaties establishing bilateral right-obligation relationships between WTO members.  

Nonetheless, it must be recalled that the reciprocal versus integral distinction does not normally apply to treaties in their entirety.  Indeed, even some rules in the WTO treaty are of the integral type, not because they are substantively more important than others, but for internal procedural/institutional reasons.  The WTO integral rules in question are those relating to the operation of WTO bodies.  When it comes to WTO rules setting out, for example, voting procedures, procedures on accession, the nomination of chairpersons or composition of certain WTO bodies, such rules must necessarily apply equally to all WTO members.  The very nature of these procedural rules implies that their breach or inter se deviation would necessarily constitute breach towards all other WTO members (irrespective of trade or trade potential).  As Schermers pointed out:  “An organization can have only one constitutional structure.  An amendment, for example, which expands the Executive Board of the organization from 18 to 24 members cannot be applied for some member States only”.  Hence, inter se modification of such institutional/procedural provisions cannot be tolerated, nor can state-to-state suspension of the obligations deriving from these provisions be legal as a form of countermeasures.  However, the importance of these provisions being of the integral type are theoretical only (why would WTO members, inter se, want to change, for example, the election procedure of chairpersons?).  What counts is that the substantive trade provisions in the WTO treaty are reciprocal in nature.

Having applied the general criterion to WTO obligations, we next elaborate on the main, underlying reasons why WTO obligations are reciprocal.  We then attempt to explain why it is sometimes (mistakenly) thought that they are integral.
2.	Three underlying reasons why WTO obligations are bilateral obligations

The object of trade:  state-to-state

Firstly, and most importantly, trade is and remains a bilateral happening.  Goods or services from one country are being exported or transferred to one other country.  The rights and obligations negotiated in the WTO are aimed at ensuring market access for a given product from member A into the market of member B.  In that sense, the WTO treaty is not all that different from the Vienna Convention on Diplomatic Relations (the standard example, referred to earlier, of a multilateral treaty imposing obligations of a bilateral/reciprocal nature):  in the Vienna Convention, rights and obligations relate to diplomats sent from one country to another;  the WTO treaty is about market access for goods from one country into another country.  In the end, all WTO members may have similar market access rights (because of the MFN principle), but the rights thereby obtained remain trade-related, hence bilateral, in nature.  Equally, a breach of WTO trade liberalisation obligations may have economic effects on more than one WTO member, because of the increased economic interdependence between states.  But this is not the same as saying that a breach of WTO obligations necessarily affects the rights of all other WTO members, the way, for example, human rights or certain environmental law breaches do.  A breach of WTO trade rules may affect a number of members individually, but it does not amount to an offence of the collective right or conscience of all state parties, the way a human rights breach does.
 
Trade (and hence WTO obligations) are international par excellence.  A state cannot trade with itself.  All WTO obligations relate, indeed, to foreign goods, foreign services or foreign service suppliers.  Necessarily international, trade is also inherently bilateral.  It takes the form of a physical or economic transfer of a unit from one country to another country.  The benefits of WTO market access rights, as well as the welfare effects of compliance with WTO obligations, are spread over all WTO members (respectively, because of the MFN principle and a more efficient allocation of resources world-wide).  But this collective effect does not negate the inherently bilateral character of trade and trade obligations.  

The object and implementation of human rights and environmental treaties are, in contrast, a national matter.  Especially respect for human rights is a matter between public authorities of a state and its own nationals.  Steps taken to protect the environment are also national:  laws and regulations are passed that set internal environmental standards within the territory of a particular state.  Obviously, although human rights and environmental obligations are, in terms of object and implementation, a national or domestic matter, they are international and collective in terms of the values they protect and the effects they want to avoid.  Respect for human rights has been elevated to the international level mainly because of the collective/universal values it seeks to achieve.  Protection of the environment has been “internationalised” for reasons of effectiveness:  environmental pollution knows no borders, hence for a country to effectively protect its environment it must co-operate with other countries.  As a result, breach of environmental and, especially, human rights obligations becomes of international interest, but this interest is essentially collective.  Quite often (as will be the case of, for example, violations of the Kyoto Protocol) not one particular state will be more affected than another.  The interest protected is collective, not bilateral.  

In sum, although trade is inherently international its obligations are bilateral; whereas human rights and environmental protection are inherently national, most of its obligations are collective.

The objective of trade:  an instrument, not a value

Secondly, unlike, for example, the prohibition of genocide or the protection of human rights or the environment, trade and the liberalisation of trade is not a value.  It is not sought after for the achievement of some "global common" that transcends the sum total of individual state interests.  Trade is not a value, it is only an instrument.  It is an instrument to increase the economic welfare of all states.  But the increase in welfare thus created by trade does not exceed the sum of economic welfare experienced by its composite members.  Of course, it can be expected that higher economic welfare will translate itself also into social and other benefits, but this would be the result mainly of what states or private operators themselves decide to do with their welfare, not a direct consequence of trade or WTO rules.  

Trade and WTO provisions seeking to enhance trade are, therefore, not like, for example, the Genocide Convention where, in the words of the ICJ:  "the contracting States do not have any interests of their own; they merely have, one and all, a common interest, namely, the accomplishment of those high purposes which are the raison d’être of the convention.  Consequently, in a convention of this type one cannot speak of individual advantages to States, or of the maintenance of a perfect contractual balance between rights and duties”.  The same has been said in respect of human rights treaties.  As the Inter-American Court of Human Rights pointed out:  “human rights treaties … ‘are not multilateral treaties of the traditional type concluded to accomplish the reciprocal exchange of rights for the mutual benefit of the contracting States’; rather ‘their object and purpose is the protection of the basic rights of individual human beings, irrespective of their nationality, both against the State of their nationality and all other contracting States’”.  Or as the ECHR noted:  “the purpose of the High Contracting Parties in concluding the Convention was not to concede to each other reciprocal rights and obligations in pursuance of their individual national interests but to realise the aims and ideals of the Council of Europe, as expressed in its Statute, and to establish a common public order … [I]t follows that the obligations undertaken by the High Contracting Parties in the Convention are essentially of an objective character, being designed rather to protect the fundamental rights of individual human beings from infringement by any of the High Contracting Parties than to create subjective and reciprocal rights for the High Contracting Parties themselves”.  

The same objective or “integral” nature has been attributed to EC treaties.  This was done not so much because of the “higher values” protected by EC treaties, but because EC law was construed as setting up a “new legal order” that confers rights on individuals and is supreme to national law.  In addition, under EC law elements of exclusive competence have been granted to EC institutions (e.g., to regulate areas such as external trade).  In that sense, EC treaties have become a form of domestic law, in respect of which member states (much like individuals in internal law) have no competence to deviate from inter se.  To that extent, obligations under EC law can, indeed, be characterised as integral in nature. 

WTO obligations, in contrast, give states an instrument to achieve other "nobler" goals.  Since, therefore, the WTO treaty is only an instrument to achieve certain other goals, agreements modifying the WTO treaty inter se in pursuit of these other goals must, generally speaking, be accepted as long as they do not affect the rights of third parties.  This is one of the major consequences of characterising WTO obligations as bilateral/reciprocal in nature.

The negotiation, re-negotiation and enforcement of WTO obligations

Thirdly, the fact that WTO obligations are reciprocal in nature can be deduced from the way they are negotiated and re-negotiated and, in particular, with reference as to how they are enforced. 

WTO obligations, especially those set out in country-specific schedules of concessions, were negotiated first state-to-state, on a bilateral level:  state A gives and takes; state B does the same.  This bilateral and mutual reduction in trade restrictions is then multilateralised and applied, respectively, by state A and state B in their bilateral relationships with all other WTO members.  As the Appellate Body remarked:  “Tariff negotiations are a process of reciprocal demands and concessions, of ‘give and take’”.  The ultimate aim of this “give and take” exercise is to achieve an appropriate balance of trade concessions.  Or as the third preamble to the Marrakesh Agreement put it, the underlying objectives of the WTO are to be achieved by “entering into reciprocal and mutually advantageous arrangements”. 

Also the way GATT and GATS concessions are re-negotiated under GATT Art. XXVIII and GATS Art. XXI proves the reciprocal nature of WTO obligations.  Essentially, only other WTO members with a substantial trade interest must be involved and agree to the re-negotiated list of concessions.  Re-negotiation, once again, happens largely on a bilateral level.

Crucially, however, the taste of the pudding comes with the eating:  the way WTO obligations are enforced is exclusively bilateral. WTO dispute settlement does not, in the first place, tackle breach, but rather nullification of benefits that accrue to a particular member.  Panel and Appellate Body proceedings only examine claims made by one WTO member against one other WTO member.  Most importantly, in case the defendant loses and does not comply within a reasonable period of time, the winning state will be authorised to impose state-to-state countermeasures against the losing state (DSU Art. 22).  This exclusively bilateral modality of enforcement of WTO rules is an important indication that most WTO obligations are reciprocal in nature.  Especially the fact that the WTO treaty allows one member to suspend its WTO obligations as a form of countermeasure towards one other member proves that WTO obligations are not of the integral type.  If WTO obligations were of the integral type, their inter se suspension would necessarily affect the rights of all other WTO members and thus fall afoul of the pacta tertiis principle (confirmed in Art. 58 of the Vienna Convention) as well as the general rule that countermeasures may suspend only rights of the violating state, not of any third state.  Although third states may well feel an economic effect of the inter se suspension (an effect that may be positive or negative), their WTO rights will not normally be affected.  In respect of integral obligations the situation is different:  their inter se suspension or modification cannot be tolerated.  The obligation, in those cases, is of an "integral" type in that it ought to be respected in all circumstances (unless, of course, exceptions are provided for), irrespective of the conduct of other states.  This explains, for example, why fundamental human rights obligations (which are obligations of the integral type) cannot be suspended in response to breach:  their suspension towards the wrongdoing state would not only affect that state, but also breach the rights of all other contracting parties.

Of course, the general bilateral mode of enforcement of WTO rules cannot as such be seen as conclusive proof that all WTO obligations are reciprocal in nature.  Human rights and environmental obligations (most of which are accepted as being of an integral nature) can also be enforced on a purely bilateral, state-to-state basis (although under these regimes a collective non-compliance mechanism is more common).  What such integral obligations would, nonetheless, not allow for is the suspension of obligations as a form of retaliation, the way WTO suspension works.  In that sense, WTO suspension as a form of countermeasures is, in and of itself, sufficient proof that WTO obligations are not integral in nature.  At the same time, although WTO obligations are reciprocal in nature, nothing prevents WTO members from setting up a collective non-compliance mechanism along the lines of certain environmental treaties (to some extent, the trade policy review mechanism does exactly that).  Such collective non-compliance mechanism would not alter the character of WTO obligations and somehow transform them into integral obligations simply because they are enforced collectively.  The efficient implementation of WTO rules may, indeed, be well, if not better, served by a collective compliance mechanism, instead of the current bilateral, state-to-state litigation system centred around breach and bilateral countermeasures.
3.	Three features of WTO obligations which could mistakenly lead to the conclusion that they are integral in nature 

Trade liberalisation is beneficial to all WTO members

A first confusion that could arise is to take the increase in global welfare that trade liberalisation (and thus most WTO obligations) brings about, as evidence that WTO obligations are a “global common”, in the collective interest, and, for that reason, must be integral in nature.  Trade liberalisation is, indeed, in the general interest in that it should increase overall global welfare as a result of a better allocation of the world's resources, including the welfare of the state making a particular trade "concession".  Much like environmental obligations of a mostly integral nature, WTO rules are, therefore, in the "general interest".  However, unlike environmental obligations, the interest achieved by WTO obligations remains a compilation of individual welfare increases, not the achievement of a “global common”, such as the preservation of the planet’s climate system, which transcends the individual benefits of individual states.  The fact that engaging in an obligation is to everyone’s individual benefit, including the one engaging in the obligation does not mean that it is in the collective interest in the sense of “a common interest, over and above any interests of the States concerned individually”.

After all, the fact that the WTO treaty, with its trade liberalising obligations, is in the interest of all WTO members may not be that special.  Is not every international treaty concluded by states supposed to be in the mutual interest of these states?  This point is best illustrated with reference to the Vienna Convention on Diplomatic Relations, generally accepted as setting out reciprocal obligations.  There as well, the fact that the provisions of this Convention are undoubtedly in the “general interest” of all states (as confirmed by the ICJ in the Diplomatic and Consular Staff case), does not alter the bilateral/reciprocal nature of the obligations they set out.

Finally, to state that trade liberalisation is, generally speaking, beneficial to all WTO members is one thing, to say that each and every WTO rule is of this “public interest” nature, quite another.  As Benedek pointed out:  “the relevance of the ‘legal economics’ in international economic law is questioned in view of the often strong political element involved in international economic relations which makes it unrealistic to regard the GATT rules from the perspective of a kind of ‘economic law of nature’”.  Witness, for example, WTO rules on anti-dumping which for many do not make economic sense and the GATT/WTO’s reluctant incorporation of the agricultural and textiles sector into mainstream trade liberalisation rules, both as a result of strong political lobbying by developed country interests.
 
MFN "multilateralises" all trade advantages, but it does not transform these advantages into a "global common"

The multiple MFN obligations set out in the WTO treaty, the cornerstone of the multilateral trading system, ensure that any trade advantage a country gives to another must be "multilateralised" and granted to all WTO members.  As a result, MFN surely makes bilateral concessions collective in the sense that they must go to all other WTO members.  But in substance, this "collectivisation" is nothing more than a duplication by the number of WTO members of the original bilateral concession.  The bilateral concession is thereby granted from state to state to all other WTO members.  It does not, by means of MFN, transcend into some "global common", more valuable than the sum total of the individual benefits it procures to each WTO member.  Looked at from a different angle, MFN is, of course, an obligation owed towards all WTO members, but when member A discriminates only member B (e.g., by banning all imports coming from B), this MFN breach can hardly be said to affect the MFN right of members C, D and E (who can continue to export to member A, arguably even more so than before given that the ban has stopped the supply coming from member B).

Breach of a WTO obligation by one member is likely to affect many other WTO members

Finally, given that (i) compliance with WTO rules normally achieves an increase in welfare world-wide and (ii) the economic inter-dependence between states is ever increasing, a breach of WTO obligations by one member is likely to affect, directly or indirectly, the economic interests of many, sometimes all, other WTO members.  This may wrongly be interpreted as granting a form of actio popularis to all WTO members for each and every breach of WTO rules, irrespective of the states involved.  In turn, given that all WTO members could then (under this wrong assumption) complain about any WTO breach, this element could be mistakenly seen as proof that WTO obligations are of an erga omnes partes or integral nature.

In EC – Bananas the Appellate Body decided that the United States could bring a case under GATT even though it hardly produces bananas and has not yet exported any.  The Appellate Body quoted with approval the following remark from the panel report:  

“with the increased interdependence of the global economy … members have a greater stake in enforcing WTO rules than in the past since any deviation from the negotiated balance of rights and obligations is more likely than ever to affect them, directly or indirectly”.

One must, however, distinguish three issues:  firstly, when does a WTO member have legal standing to bring a WTO complaint (the matter at issue in EC – Bananas); secondly, what is required for a WTO complaint to be validly established; thirdly, what are the consequences of validating a WTO complaint?  We examine these three distinct issues in turn.  

Standing

On the first issue of standing, the Appellate Body in EC – Bananas made the rather astonishing finding that in order to bring a case under the DSU, no “legal interest” is required.  In particular, it did “not read any of [the PCIJ/ICJ] judgements [referred to by the EC] as establishing a general rule that in all international litigation, a complaining party must have a ‘legal interest’ in order to bring a case”.  

Looking at the cited international case law and the ILC Final Draft Articles, it may be so that not much reference is made there to “legal interest” (in the sense of an interest to see the law abided by), but this is so because normally more than a “legal interest” is needed for a state to have standing, namely one must prove the existence of a “legal right”.  Any breach of international law could be said to affect the legal interest of all other states, that is, the interest of states to see respect for the rule of law in general (even if these states draw no individual rights from this law).  But this “legal interest” is not normally enough for a state to invoke responsibility for breach.  Even if Art. 48 of the Final ILC Draft Articles grants certain rights to enforce state responsibility to states that are not “injured States”, but merely have a legal interest, this occurs only for international norms of a certain  nature, e.g., obligations erga omnes or erga omnes partes; not for obligations of a reciprocal nature, such as most WTO obligations.  As Crawford noted in his Third Report:  

"outside the field of 'integral' obligations, or obligations erga omnes partes, … it is doubtful that States have a right or even a legally protected interest, for the purposes of State responsibility, in the legal relations of third States inter se".  

Hence, even for those breaches of international law in respect of which the most lenient rules on standing apply (say, erga omnes or jus cogens obligations), standing is granted because of the existence of a “legal interest”.  Hence, in all cases where standing is acknowledged, at least a “legal interest” must be pointed at.  Therefore, the only way to make sense of the Appellate Body finding that no “legal interest” is required, is to assume that the Appellate Body did not mean to refer to “legal interest” in its usual sense of “interest to see the law abided by”, but understood this term to mean, for example, a requirement of proof of actual damage or trade diversion.

It is important to recall what the Appellate Body did not state in EC - Bananas.  It did not say that a purely “legal interest” to see WTO rules abided by is sufficient for any WTO member to have standing in respect of all possible breaches of WTO law.  On the contrary, it stated that there is no requirement of “legal interest”. Of course, like any WTO member (and arguably even non-WTO members) the United States did have a “legal interest” to see GATT rules abided by.  In addition, however, the Appellate Body was careful enough to base its conclusion that the United States did have standing under GATT on other factors as well (not related to purely “legal interest”):  the United States was a producer of bananas and hence a potential exporter, the US market for bananas was potentially affected by the EC regime in terms of world supplies and prices and the GATT claims were inextricably interwoven with those under GATS for which the United States did unmistakably have standing.  The Appellate Body stressed that 

“taken together, these reasons are sufficient justification … This does not mean, though, that one or more of the factors … would necessarily be dispositive in another case”.  

The Appellate Body forgot, however, to mention one other obvious but crucially important factor for standing to be granted, namely the fact that the EC import regime for bananas, if found to be discriminatory the way the United States claimed it to be, was favouring ACP countries and hence, at least in theory, discriminating all other WTO members, including the United States.  The measure at issue was not a measure discriminating only one other WTO member (e.g., a member other than the United States), nor a trade restriction that did, on the books, not apply to US exports, the way, for example, an allegedly WTO inconsistent anti-dumping duty imposed by the EC on cement from Mexico would have nothing to do with US rights under the WTO.  

In sum, based on a close reading of the Appellate Body decision in EC – Bananas, the mere fact that a WTO member breaches WTO rules does not suffice for all other WTO members to have standing to seek redress for this breach.  A purely “legal interest” is not enough.  For a member to have standing the inconsistent measure must, at least in theory, apply to the trade of that member.  An anti-dumping duty imposed by the United States on steel from Japan only cannot be challenged by the EC; nor can the United States complain about Zambia discriminating exports from Nigeria only.  In addition, even if the measure does de jure apply to the trade from that other member, some proof must be provided that either actual or potential trade flows are being restricted and/or that the member is otherwise economically affected (e.g., by an increase in world prices, as referred to in EC - Bananas).  The first condition will, in effect, constitute a bigger hurdle than the second.  Indeed, if the measure does, on the books, apply to the complainant, trade potential or missed trade opportunities will be easily proven, in particular given the economic inter-dependence of WTO members.  

The fact that these two conditions for standing do exist, and that, therefore, the WTO does not know an actio popularis, shows that WTO obligations are reciprocal in nature, not integral or binding erga omnes partes.  Hence, absence provisions in the WTO treaty to the contrary, the general rule in Art. 42 (a) of the Final ILC Draft Articles applies.  That is, a WTO member can only bring a complaint against another WTO member in case the obligation allegedly breached is owed to it “individually”.

Here again, the traditional example of reciprocal/bilateral obligations, namely those in the Vienna Convention on Diplomatic Relations, is instructive.  As is the case for breach of WTO obligations, breach of obligations under the Vienna Convention is mostly likely to affect also other state parties.  However, this does not necessarily give those other states standing to invoke responsibility for the breach, nor does it detract from the bilateral/reciprocal nature of Vienna Convention obligations.  Only in case the breach is one of an obligation owed to the state “individually” -- say, only in case the alleged wrongdoer has violated diplomatic law as against diplomats of the complainant state -- will the complainant state have standing. 

As pointed out, nothing prevents states, when concluding a bilateral/reciprocal treaty like the WTO treaty, from “contracting out” of those general international law rules on standing.  Hence, WTO members (or, for that matter, the Appellate Body) could well decide that, for whatever policy reason, it is desirable to make breach of WTO law challengeable by all WTO members, irrespective of the breach.  Such would not, in and of itself, change the nature of WTO obligations as reciprocal obligations.  (In contrast, the fact that, as the law now stands, not every WTO member can complain about breach of WTO law, does prove that WTO obligations are reciprocal in nature, not binding erga omnes partes).  The main argument against giving standing to all WTO members, based on a general legal interest to see the treaty abided by, is the risk of effectively appointing a number of powerful states as public prosecutors or policemen, with the result that especially (or only) obligations in the particular national interest of those states would be enforced.  In the WTO, granting such actio popularis could mean that WTO agreements on, say, intellectual property or trade in services are more often judicially enforced than, for example, the agreements on Agriculture or Textiles and Clothing.

Breach 

The second condition for a member to have standing (proof of trade effects or, at least, trade potential or opportunities) is directly related to the conditions for a breach of WTO obligations to be established.  Since standing essentially depends on the existence of a legal right, proof of a legal right will be inextricably linked to proof of breach.  Now, for a breach of WTO rules to be established, it is generally accepted in GATT/WTO case law that a complainant is not required to prove that actual trade flows have been diverted.  Proof of trade opportunities being effected will be enough.  This explains, at the same time, why prove of trade effects is not a requirement either in terms of standing.  

Nonetheless, as pointed out earlier, for a complainant to prove that a measure violates WTO rules is not enough for that measure to be condemned by a panel.  In addition, the complainant must point at nullification or impairment of benefits accruing to it.  As noted above, this element supports the view that WTO obligations are reciprocal in nature.  However, DSU Art. 3.8 provides for a presumption to the effect that breach “is considered prima facie to constitute a case of nullification and impairment”.  This is further explained to mean that “there is normally a presumption that a breach of the rules has an adverse impact on other Members”.  However, as the Appellate Body noted, Art. 3.8 is about “what happens after a violation is established”.  It does not relate to the issue of standing required in order to be allowed to invoke breach.  In other words, to say that nullification of benefits is presumed once breach is established (as Art. 3.8 does) is not the same as saying that all WTO members have a right to complain about any WTO breach.  

Even so, the second criterion referred to above for a member to have standing (proof of at least trade potential or opportunities) must run parallel with the requirement for there to be nullification.  In EC – Bananas, for example, the Appellate Body referred to the same factors under both standing and nullification under DSU Art. 3.8, namely the United States being a producer and potential exporter and the possible effects on the US internal market.  It noted that “[t]hese matters that we have already decided are relevant to the question of the standing of the United States under the GATT 1994.  They are equally relevant to the question whether the European Communities has rebutted the presumption of nullification or impairment”.  

Consequently, once a WTO member has been granted standing, in particular, once it has met the second criterion for it to have standing, it must necessarily meet also the nullification and impairment condition in DSU Art. 3.8.  As a result, once standing accorded and once breach established, the presumption of nullification must, for all practical purposes, be irrebutable.  

Consequences of breach

Although breach of WTO rules may be successfully invoked by a number of WTO members (meeting, first, the two rather lenient conditions for standing and, second, the relatively wide definition of breach, both referring to trade opportunities, not trade effects), a finding of breach of WTO rules is a purely bilateral matter.  Quite often, whether or not there is breach will actually be dependent on the complainant (are its exports, for example, “like products” as compared to the domestic products allegedly protected in breach of, say, GATT Art. III:4?).  A finding of WTO breach is bilateral also in the sense that only the complainant, not other WTO members, may directly rely on it.  Only the complainant may suspend concessions if no implementation follows, not other WTO members.  In addition, the fact that other WTO members have exactly the same measure in place as the one found to be in breach does not give other WTO members any rights to suspend concessions.  A new state-to-state complaint must be lodged against these equivalent measures for their WTO illegality to be conclusively established. 

These bilateral consequences of breach, combined with the requirements for standing set out above and the state-to-state definition of breach (including the condition of member-specific nullification), are proof that WTO obligations are not integral, but reciprocal.

C.	Conclusion on WTO obligations as bilateral obligations (focusing on inter se modifications pursuant to Art. 41 of the VCLT)

The fact that WTO obligations are bilateral/reciprocal obligations (not multilateral/integral obligations) puts them in perspective.  It stresses their relative importance as obligations of an essentially contractual type that can, in principle, be deviated from or suspended inter se (in line with Arts. 41 and 58 of the VCLT).  They are not integral in the sense of being immutable obligations to be respected at all times and as between all WTO members, irrespective of other norms of international law.  WTO obligations are, in this sense, framework obligations only or lex generalis that can be supplemented or deviated from, as between some or all WTO members, by other rules of international law (especially, rules that are of an integral type).  

WTO law is but a branch of public international law.  Given its reciprocal nature, WTO law will, moreover, have to allow for and give way to a number of other rules of international law.  The fact that some WTO members agree to deviate from WTO obligations in their inter se relations only (e.g., by mutually agreeing to condition their trade on respect for human rights) must, in principle, be accepted, given the reciprocal nature of WTO obligations.  As long as the rights of other WTO members are not affected, these other WTO members, not party to the inter se deviation, cannot complain about these purely inter se contractual changes.  The requirements for other members to have standing to challenge such inter se deviations will then, indeed, not be met (on the books, the measure does not even apply to their trade, not even their potential trade).  If WTO obligations were, however, of the integral type, no such inter se modifications could have been tolerated.  

Applying these conclusions to, for example, conflicts between WTO law (of a bilateral nature) and provisions in multilateral environmental agreements (MEAs) or human rights treaties (mostly of a multilateral/integral nature), the following solutions can be offered.  

In case the WTO rule can be defined as the later in time, it can be seen as an inter se agreement modifying certain integral MEA or human rights obligations.  If this is the case -- i.e., if the WTO rule deviates from integral obligations as between WTO members only -- then WTO rules would not only affect WTO members but also third party rights (i.e., rights of non-WTO members, party to the human rights treaty or MEA) or even be incompatible with “the effective execution of the object and purpose of the [human rights or MEA] treaty as a whole” (in the sense of Art. 41, para. 1(b)(ii)).  Consequently, as between parties to the MEA or human rights treaty, the particular WTO provision, to the extent of the conflict, would then be illegal under Art. 41 VCLT.  In other words, the conflict should then be decided in favour of the earlier MEA or human rights provision. This would be the result of Art. 41 VCLT.  The fact that the WTO rule is the lex posterior under Art. 30.4(a) VCLT does not alter this solution.  Art. 30.5 VCLT explicitly makes the operation of Art. 30.4 subject to Art. 41. 

In contrast, if the human rights treaty or MEA would be the later in time, it must be recalled that inter se agreements modifying reciprocal obligations such as those in the WTO treaty are, in principle, accepted (pursuant to Art. 41 VCLT).  The human rights treaty or MEA could then be defined as an inter se agreement deviating from WTO rules as between the parties to the human rights treaty or MEA.  Given the reciprocal nature of WTO obligations, this inter se agreement is unlikely to be illegal under Art. 41 (unless it affects the rights of third parties).  Hence, in the event of conflict, the later human rights treaty or MEA would not be prohibited as an illegal inter se deviation.  It should then prevail as the lex posterior pursuant to Art. 30.4(a) (of course, only as between the parties to both norms).  The earlier WTO rule is then, however, not illegal.  It is simply the lex prior having to give way inter se to the later human rights treaty or MEA.  

In sum, irrespective of the actual timing of the two norms, in the event of conflict between a WTO rule of the reciprocal type and a human rights or MEA obligation of an integral nature, the human rights or MEA obligation must, either pursuant to Art. 41 VCLT or pursuant to Art. 30.4(a) VCLT, prevail in the relationship between two parties that are bound by both norms.

Take the example of conflict between a WTO obligation not to restrict trade in product X (assuming that GATT Art. XX does not allow for trade restrictions on product X) and an MEA or human rights obligation, of the integral type, to restrict trade in product X because product X is defined as an environmentally or socially unfriendly good.  As between states that are bound by both rules, the MEA/human rights rule must prevail, irrespective of whether it comes earlier or later in time.  If it comes later in time, it prevails as the lex posterior under Art. 30.4(a) VCLT.  If it is the earlier in time, it cannot, as an integral obligation, be deviated from inter se, by the later WTO rule.  
II.	WTO OBLIGATIONS ARE CONTINUING OBLIGATIONS

A.	Interpreting the WTO treaty:  “Contemporaneous” or “evolutionary” interpretation?
1.	The distinction explained
The question of contemporaneous versus evolutionary interpretation arises “whenever a rule refers to a concept the scope or significance of which has changed in the course of time”.  Such change may constitute an evolution in the law or an evolution in the way contracting parties to a treaty understand a concept (without such new understanding being reflected in new law).  The words of Art. 31.3(c) VCLT leave this question open.  Art. 31.3(c) requires that a treaty interpreter takes into account, together with the context, “any relevant rules of international law applicable in the relations between the parties”.  It does not limit this reference to other rules of international law to those that existed at the time of conclusion of the treaty, nor does it explicitly include other law that had developed at the time of application.

The principle of contemporaneity requires that a juridical fact be appreciated in the light of understanding and law contemporary with it. For example, when the ICJ interpreted the provisions of Article 20 of the treaties between the United States and Morocco of 1787 and 1836 (substantially identical in terms) in the United States Nationals in Morocco case, it stated that “it is necessary to take into account the meaning of the word ‘dispute’ at the times when the two treaties were concluded”.  This principle of contemporaneity is generally seen as the rule.  In other words, the rule is that in interpreting terms in, for example, the WTO treaty, reference is to be had to their meaning in international law in April 1994, i.e., the time WTO agreements were concluded.  On that basis, it would seem that the reference to the Berne, Paris and Rome Conventions in the TRIPS Agreement is a reference to these agreements as they stood in April 1994, i.e., at the time of conclusion of the WTO treaty.  The incorporation of these WIPO conventions into the WTO treaty would only be a dynamic one -- automatically incorporating also modifications brought to these conventions in WIPO -- in case there were a clear indication on behalf of the drafters of the TRIPS agreement to that effect.

There is, however, scope for exception to this principle of contemporaneity.  Indeed, already in the preparation of the VCLT itself, it was realised that 

“the content of a word, e.g. ‘bay’ or ‘territorial waters’, may change with the evolution of the law if the parties used it in the treaty as a general concept and not as a word of fixed content”.  

This reflects the so-called “evolutionary approach” to treaty interpretation. This approach has been followed in three subsequent ICJ judgements, interpreting, for example, the term “territorial status”.  In those cases, the ICJ referred to the need to interpret the treaty “within the framework of the entire legal system prevailing at the time of interpretation”.       

To answer the question as to which interpretative method must be applied (contemporary or evolutionary approach), the intention of the parties to the treaty must be decisive.  
2.	The distinction applied to the WTO treaty
Where does this leave us when it comes to interpreting terms used in the WTO treaty?  One Appellate Body stands out in this respect.  In its report on US – Shrimp/Turtle the Appellate Body had to decide whether the terms “exhaustible natural resources” in GATT Art. XX(g) included only living resources or also non-living resources (in casu, certain sea turtles).  It found as follows: 

“The words of Article XX(g), ‘exhaustible natural resources’, were actually crafted more than 50 years ago.  They must be read by a treaty interpreter in the light of contemporary concerns of the community of nations about the protection and conservation of the environment”.

In support of this evolutionary interpretation, the Appellate Body referred to the preamble attached to the 1994 WTO Agreement which mentions "the objective of sustainable development".  It continued as follows:

“From the perspective embodied in the preamble of the WTO Agreement, we note that the generic term ‘natural resources’ in Article XX(g) is not ‘static’ in its content or reference but is rather ‘by definition, evolutionary’. It is, therefore, pertinent to note that modern international conventions and declarations make frequent references to natural resources as embracing both living and non-living resources”.

Based on the preamble to the WTO Agreement and “the recent acknowledgement by the international community of the importance of concerted bilateral or multilateral action to protect living natural resources”, the Appellate Body concluded that “it is too late in the day to suppose that Article XX(g) of the GATT 1994 may be read as referring only to the conservation of exhaustible mineral or other non-living natural resources”.

Are the terms in GATT Art. XX(g) special, or should this evolutionary approach be applied to the interpretation of most or all WTO provisions?  As noted earlier, this will depend on the particular provision and the intentions expressed therein by the drafters.  Hence, much like the bilateral/multilateral distinction discussed above, one can rarely say that an entire treaty must be interpreted in an evolutionary way.  Each provision must be examined on its own merits.  Nonetheless, three arguments can be made in support of evolutionary interpretation becoming the rule, rather than the exception, when it comes to interpreting the WTO treaty.  

Firstly, WTO obligations are increasingly of a regulatory nature. As compared to the GATT (based largely on country-specific tariff concessions), the character and underlying foundation of most WTO rules has changed.  WTO agreements such as the SPS or TRIPS agreement are unrelated to the idea of balancing trade concessions that are (like in GATT or GATS) additional to the rules set out in the agreement itself.  Today, most WTO rules set out general standards and conditions for state conduct, which are binding not as part of some ephemeral balance of concessions, but as a result of their inherent and indefinite juridical force.  In that sense, the WTO treaty is increasingly a law-making treaty or traité-loi.  One of the features of general regulatory provisions is that they use broad, unspecified terms, such as “exhaustible natural resources”, “public morals” or “essential security interests” in GATT Articles XX and XXI.  As the Appellate Body found in US – Shrimp/Turtle this is an indication that evolutionary interpretation was intended.  It is, indeed, an indication that WTO Members wanted these terms to evolve with society and international law or, at least, should have realised that the vagueness of these terms would result in their meaning being open to discussion and variation depending on the context and times.  

In this context, interpreting most WTO provisions in an evolutionary manner seems both logical and necessary.  The same attitude was taken by the European Court of Human Rights when interpreting the European Convention on Human Rights, another “regulatory treaty”.  In the Tyrer case, for example, it found as follows:  

“The Court must also recall that the Convention is a living instrument which … must be interpreted in the light of present-day conditions … the Court cannot but be influenced by the developments and commonly accepted standards in the penal policy of the member States of the Council of Europe in this field”.

Secondly, pursuant to Art. 31.1 VCLT, the terms of the WTO treaty must be interpreted “in their context and in the light of its object and purpose”.  When it comes to regulatory treaties, this object and purpose soon leads a life that is largely independent and de-linked from the subjective and temporal intentions of the treaty’s original drafters.  It becomes an objective, dynamic regime where “the whole is greater than the sum of the parts”.  As it was noted by a 1986 arbitral tribunal in a dispute between Canada and France:  

“Dans les traités normatifs ou institutionels conclus entre un nombre élevé d’Etats et pour une durée indéterminée, le but du traité se détache aisément des finalités poursuivies par chacun des contractants primitifs et acquiert une autonomie objective que l’interprète ne peut méconnaître ».     

Consequently, when interpreting WTO provisions account must be had of the WTO’s object and purpose as it may evolve over time. 

Thirdly, most WTO provisions can be said to be of a “continuing nature” in the sense that WTO members regularly renew their consent to them by means of implementing, applying, monitoring and reconfirming these provisions in the context of the WTO as an international organisation.  As noted by Simon in respect of treaties establishing international organisations:

“l’accord de volontés qui a présidé à la conclusion de la convention ne s’est pas épuisé dans la rédaction d’un texte; l’application d’une telle convention suppose nécessairement le renouvellement permanent de l’adhésion des Etats membres au contenu de normes juridiques dont l’instrument signé ne constitue qu’une expression solonnelle, mais, par essence, éphémère.  Or la fonction de l’interprète est … de donner effet au consensus continu des parties plutôt qu’à des volontés cristallisées à la date de signature … ou, si l’on préfère, de reconnaître dans les traités constitutifs la présence d’ ‘effectivités en action ‘ qui imposent une interprétation ‘évolutive’ des intentions des fondateurs de l’organisation”.

The fact that WTO members could thus be said to “continuously” re-confirm their consent to the WTO treaty pleads in favour of interpreting this treaty in an evolutionary manner, that is, in line with understandings and law at the time of its application.

B.	Putting a time-label on the WTO treaty in case it conflicts with another treaty

The third and last reason above in support of interpreting the WTO treaty in an evolutionary manner (WTO provisions can be said to be of a “continuing nature”) provides an appropriate bridge to the other question of timing we set out to examine.  That is, the question of putting a time-label on the WTO treaty in case it conflicts with another treaty so as to apply the lex posterior rule (pursuant to which the treaty later in time prevails).  

Art. 30.3 and 4 VCLT provide for the following conflict rules in respect of “Application of successive treaties relating to the same subject-matter”:

3.	When all the parties to the earlier treaty are parties also to the later treaty but the earlier treaty is not terminated or suspended in operation under article 59, the earlier treaty applies only to the extent that its provisions are compatible with those of the later treaty.

4.	When the parties to the later treaty do not include all the parties to the earlier one:

(a)	as between States Parties to both treaties the same rule applies as in paragraph 3;

(a)	as between a State Party to both treaties and a State Party to only one of the treaties, the treaty to which both States are parties governs their mutual rights and obligations.

 For present purposes, we shall examine only the question of timing, that is, the terms “successive treaties”, “earlier treaty” and “later treaty”, as referred to in Art. 30 VCLT.
1.	Treaties as instruments with a time-label 
The focus of the VCLT is treaties as an instrument, not obligations deriving from treaties.  Art. 30 VCLT as well deals with the application of “successive treaties” and “an earlier treaty” as opposed to “a later treaty”.  This seems to imply that the timing of treaties under Art. 30 is a question of putting a date on the treaty as an abstract instrument, not a question of defining when the treaty imposes a particular obligation as between two given states.  

This approach of putting a time-label on treaties as instruments makes sense in case one is faced with a treaty that is clearly concluded in order to amend an earlier one and where the parties to both treaties are exactly the same.  One may think here of a 1990 bilateral investment treaty between A and B which is subsequently amended by a later 2000 treaty as between A and B; or a 1994 WTO agreement which is subsequently amended by a later 2000 treaty as between all WTO members, pursuant to Art. X of the Marrakesh Agreement.  

In those instances, the domestic law analogy with “legislative intent” and “the legislator” being able to change earlier legislation by later legislation, may make sense.  In those cases, one is, indeed, faced with one homogenous bloc of states, acting, arguably, as some kind of legislator in a particular field (albeit legislation applicable only as between the parties to the treaty). 

2.	The fiction of “legislative intent” unfolded
However, the fiction of later “legislative intent” overruling another, earlier one, looses its attraction as soon as the “same context – same parties” constellation changes.  Indeed, even in respect of two AB treaties, it becomes hard to refer to one and the same “legislature” in case the earlier bilateral treaty was concluded in the context of a multilateral environmental agreement (MEA) and the later one in the context of, for example, the WTO.  A state’s consent must be seen as one and indivisible, irrespective of who negotiated the treaty, but the reality remains that in the context of an MEA a very different set of people and values are at work than those active in, for example, the WTO context.  Hence, the position of one state in one context may, indeed, be diametrically opposed to that same state’s position in another context.   

But it is not only the difference in context that may make the analogy with “legislative intent” unworkable.  In many instances -- and especially in respect of the great regulatory treaties of modern times, such as certain MEAs, UNCLOS and the WTO -- the two treaties will have a different membership.  The two treaties are then clearly the result of a different “legislature”, i.e., a different composition of states.  They will hence be the reflection of a different balance of interests and one state may well have been able to push through its interests more under one treaty than under another.  This difference will be accentuated in case a norm in one treaty context is adopted by unanimity and a norm in another treaty context is adopted by majority voting, even as between states that are parties to both treaties.  In that case, it may well be that one of the parties accepted the first norm but explicitly voted against adoption of the second norm.  Such objection cannot mean that the state in question is not bound by the second norm since it agreed to the majority voting procedure in the first place.  But it would make the comparison with one and the same “legislator” simply changing its mind over time more difficult.  

The above considerations highlight the diversity as between different treaties and the difficulty of making a domestic law analogy based on changing “legislative intent”.  Nonetheless, these difficulties must, as a general rule, be accepted as a reality of international law.  Adopting a lex posterior rule in this context may, indeed, provide a strong incentive for states to streamline their positions across international organisations and irrespective of the membership to particular treaties.  States must realise that, in principle, whatever they consent to now prevails over what they agreed on earlier, irrespective of the context in which the obligations were entered into.  

Hence, the lex posterior rule may be an important instrument that creates some order in the chaos of international law.  However, given its shaky foundation of changing “legislative intent””, it cannot be seen as an absolute rule the way it is regarded, for example, in domestic law for inter-acting statutes.  Exceptions to it must be allowed for in case the analogy with “latest legislative intent” looses touch with reality.  

3.	The difficulty of putting a time-label on a treaty as “instrument”
The lex posterior rule in Art. 30 may not only be put in doubt because of the shaky analogy it makes with changing “legislative intent”.  From a more practical point of view, it will in many cases also be difficult to “put a time-label” on a treaty.  

To begin with, it is generally accepted that the timing of a treaty for purposes of Art. 30 is determined by the date of its conclusion or adoption.  In case of the WTO treaty, for example, this is 15 April 1994.  It is not the date of entry into force that determines the timing of a treaty under Art. 30.  This was made explicit by the Expert Consultant at the Vienna Conference:

“for purposes of determining which of two treaties was the later one, the relevant date should be that of the adoption of the treaty and not that of its entry into force.  His own understanding of the intentions of the [ILC] confirmed that assumption”.  

The fact that the date of conclusion is decisive was explained with reference to the concept of “legislative intent” elaborated earlier:  “when the second treaty was adopted, there was a new legislative intention; that intention, as expressed in the later instrument, should therefore be taken as intended to prevail over the intention expressed in the earlier instrument.  That being so, it was inevitable that the date of the adoption should be the relevant one”.  That the date of conclusion counts to define a “later treaty” under Art. 30 finds support also in Art. 59 where reference is made to “conclusion of a later treaty” and “conclude a later treaty”.

Hence, it is not the difficulty of deciding between the date of conclusion, opening for signature, ratification or entry into force that makes it difficult to put a time-label on treaties.  What counts is the date of conclusion, irrespective of the fact that the treaty may have been ratified by, or entered into force for, different parties at different times.  Utilising the date of conclusion does, indeed, make logical sense when faced with a conflict between two treaties to which no parties acceded subsequently.  For example, as between a 1990 bilateral investment treaty between A and B and a subsequent 2000 bilateral investment treaty between A and B.   

The situation is more complicated in the event of treaties to which additional states have acceded. This is the case in respect of all regulatory treaties with a universal calling (such as the WTO treaty, UNCLOS, most MEAs and most human rights treaties) as well as many regional arrangements (such as the European Union, ECHR or NAFTA).  The underlying objective of these treaties is that an increasing number of states accede to it (with or without regional restrictions).  When faced with such “expanding” treaties, it becomes often untenable to stick to the date of original conclusion of the treaty.  This problem was already pointed out by Sir Ian Sinclair at the Vienna Conference itself:  

“supposing a multilateral convention was opened for signature in 1960, State A ratified it in 1961, and the convention entered into force in 1962.  Then State A and State B concluded a bilateral treaty on the same subject in 1963 which entered into force in 1964, after which State B acceded to the multilateral convention in 1965.  Which of the treaties was the earlier and which was the later?  In State A’s view, the multilateral convention was the earlier [1960] but in State B’s view it was the later [1965]”.  

The fact that the parties to a treaty did not “conclude” the treaty at the same point in time makes it impossible to put a single time-label on the treaty in question.  It necessitates a shift away from the treaty as abstract instrument to an assessment of the treaty as source of rights and obligations resting on particular states.  This fact is, moreover, a death blow to the fiction of each treaty being concluded by one and the same “legislative intent”, expressed at one point in time.  This fiction must, in turn, be brought back to a genuine principle of international law, namely the contractual freedom of states.  We next examine Art. 30 from this perspective of treaty provisions binding on particular states and contractual freedom as between the two states in question.

4.	Treaties as a source of rights and obligations as between particular parties 
Although the crucial date under Art. 30 is the date of conclusion of the treaty, Art. 30 can be activated only as between two parties for which the treaty has entered into force.  If not, there could not be conflict.  However, once the treaty has entered into force for the two states in question, i.e., once a conflict may arise, in order to put a time-label on the treaty it is not the date of entry into force that counts -- that date that may well be different for the parties involved -- but the date of conclusion of the treaty. 

But this leaves us with the situation referred to by Sinclair -- that is, the situation that prompted us to examine Art. 30 in terms of rights and obligations resting on particular states -- namely:  treaty 1 to which state A is an original member and state B acceded at a later point in time, in conflict with a bilateral treaty 2 that was concluded by A and B in between these two points of time.  One may think here of a conflict between a WTO rule and a provision in a bilateral treaty concluded in 2000 as between two parties, one of which is an original WTO member (1994), the other being a state that acceded to the WTO only in 2001.  For the original (WTO) member (state A) treaty 1 (the WTO treaty) is “concluded” at the time of the treaty’s original conclusion (15 April 1994).  Hence, for A treaty 1 is the “earlier treaty”.  In contrast, for the acceding member (state B), treaty 1 (the WTO treaty) is “concluded” at the time its accession was adopted (in casu, 2001).  Hence, for B the same treaty 1 is the “later treaty”.  The same situation would arise in case A and B are original WTO members, A concludes and becomes bound by a WTO amendment in 2000, there where B only does so in 2002 and in 2001 A and B conclude a treaty in conflict with the WTO amendment.  For A, the 2001 treaty is the later in time; for B the WTO amendment is the later in time.  In those cases, as Vierdag pointed out, 

“[p]aradoxically, as a result of the lex posterior rule laid down in paragraph 3 of Article 30, a treaty [or amendment] to which a State was quick to become a party will be set aside by an incompatible treaty to which it became a party at a later date, perhaps reluctantly.  For States that were slow in adhering to a treaty [or amendment] the effect of paragraph 3 will be that this treaty will supersede an incompatible treaty they were quick to enter into at an earlier date”. 

At this juncture, two approaches are possible.  Firstly, in application of Art. 30 one could search for the time of “convergence of state consent” in respect of the particular treaty provision.  Secondly, one could dis-apply Art. 30 all together on the ground that the two treaties are not “successive”.  We next deal with these two alternatives in turn.  

5.	Look for the “time of convergence of state consent” in respect of the treaty provision concerned
Firstly, one could submit that in circumstances where for one state the treaty is “earlier” and for the other the treaty is “later”, one ought to focus, not so much on the timing of the treaty as abstract instrument, but on the date at which the consent of the two states in question converged.  Hence, instead of focusing on the date of “legislative intent” underlying the treaty as abstract instrument, one would then focus on the date when the expression of contractual freedom of the particular states in question met.  Under this first approach, the hypothetical conflict outlined above between the WTO treaty and a bilateral treaty concluded subsequently in 2000 but before the second state acceded to the WTO in 2001, would then be resolved in favour of the WTO rule since the consent of both parties to the WTO treaty arose subsequently to that underlying the bilateral agreement (i.e., 2001, date of accession of the second state to the WTO, as opposed to 2000, date of conclusion of the bilateral treaty).  In other words, when faced with two parties for which a treaty has a different date, the latest date should then be adopted as the date reflecting the time at which both parties’ consent around the treaty emerged.  

In the context of a multilateral treaty in conflict with a bilateral treaty this approach may work.  But if one applies it also to a similar type of conflict between two multilateral treaties, the solution may be problematic for it becomes difficult to talk of an earlier versus a later convergence of state consent.  Take the example of the WTO treaty (1994) in conflict with the Carthagena Biosafety Protocol (1999).  States A and B are original WTO members which adopted the Protocol in 1999.  State C acceded to the WTO in 2000 after it had adopted the Protocol in 1999.  State D acceded to the WTO in 2001 and subsequently adopted the Protocol.  In that situation our first approach offers the following outcome:

•	as between states A and B, the Protocol prevails as the later treaty; 
•	as between states A and B, on the one hand, and state C, on the other, the WTO prevails as the later treaty; 
•	as between states A, B, C, on the one hand, and state D, on the other, the Protocol prevails as later treaty.  

This differential approach would thus mean that for some states, WTO rules prevail, for others the Protocol.  Depending on the circumstances -- i.e., is the Protocol obligation one of an integral nature? – the WTO rule may be “illegal” pursuant to Art. 41 as an inter se deviation from an integral obligation.  But if no integral obligations are involved, can this “balkanisation” of multilateral treaties be tolerated?  

As between states that both participated in the conclusion of the two treaties (in casu, states A and B), to say that the “later treaty” prevails as between them -- even if for other states this treaty may not be the later one – seems to make sense.  However, as soon as one of the treaties is the “later” in time for one party and the “earlier” in time for another party, the solution offered becomes shaky.  Indeed, in terms of state practice, would states A and B (original parties to both the WTO and the Protocol) realise that when they let C accede to the WTO in 2000 in their relationship with C, WTO rules prevail; but when they subsequently let D accede to the WTO in 2001 in their relationship with D, the Protocol prevails?

6.	Dis-apply Art. 30 – the notion of “continuing” or “living” treaties
This brings us to a second approach.  One could submit, indeed, that in situations where for one state a conflicting treaty is the earlier one, whereas for the other state it is the later one, it is impossible to define the treaty as either “earlier” or “later” in time as required in Art. 30 (for A it is “earlier” and for B it is “later”).  Consequently, the conflict in question is not one of “successive treaties”.  Hence, Art. 30 does not apply and one must have resort to other conflict rules (in particular, the lex specialis principle).    

A strong argument in support of this second approach applies when faced with a multilateral treaty of what I term a “continuing” or “living” nature.  Such multilateral treaty norms are part of a regulatory framework or legal system that was created at one point in time but continues to exist and evolve over a mostly indefinite period.  Most rules of modern multilateral conventions are of this nature, including EC treaties, WTO rules, UNCLOS and many environmental conventions and human rights treaties.  They are rules part of a framework or system which is continuously confirmed, implemented, adapted and expanded, for example, by means of the accession of new state parties (for which not only the consent of the new party is required, but also the reciprocal acceptance of all, or a majority of, existing parties).  Such treaty norms were not only consented to when they originally emerged, but continue to be confirmed, either directly or indirectly, throughout their existence, in particular when monitored and evolving within the context of an international organisation (such as the WTO).  It would be inconsistent with the genuine will of states to “freeze” this type of rules into the mould of time at which they were originally created and to label them as an expression of state consent limited to, say, 15 April 1994.  

This type of treaty norms derive from “continuing” or “living” treaties, not reflections of a “one-shot-end-all” expression of state consent.  As a result, when such treaty norm conflicts with another treaty norm, in particular another continuing treaty norm, the “guillotine” approach of time of conclusion (the later in time prevailing) may not make sense and lead to arbitrary solutions.  

Take the example of GATT 1947 and GATT 1994, on the one hand, in conflict with an MEA concluded in 1990, on the other. The GATT 1947 was concluded in 1947 and continued to exist up to 1995.  In 1994, however, the GATT 1947 was incorporated into the WTO Agreement (as part of GATT 1994) under whose umbrella also a number of new treaties were put.  As a result, when the WTO Agreement was concluded in 15 April 1994, also the provisions of GATT 1947 as incorporated into the WTO Agreement, were “re-concluded”.  Now, as against our 1990 MEA, did this re-conclusion of GATT result in a complete tabula rasa in the sense that whereas before 1994, the MEA prevailed, as of 1994, it was again the GATT that must prevail as the “later treaty”?  

If so, the same argument could be made in respect of the recent confirmation of WTO agreements at the Doha 2001 Ministerial Conference.  Indeed, the Doha Ministerial Declaration “strongly reaffirm[s] the principles and objectives set out in the Marrakesh Agreement Establishing the World Trade Organization”.  Does this mean that before Doha, agreements concluded between 1994 and 2001 prevailed over the Marrakesh Agreement, whereas after Doha, it is again the “re-concluded” Marrakesh Agreement that prevails?  In my view, this approach is erroneous and the WTO treaty should rather be seen as a “continuing treaty”.
  
Taking the time of conclusion or re-conclusion as decisive in the context of “continuing treaties”, would have an even more absurd effect when it comes to regular revisions of technical treaties.  Such technical treaties may need to be revised on a regular basis to keep track of technological developments.  But does this mean that after each revision, the revised treaty prevails again as against treaties concluded before the revision?  If so, technical treaties subject to regular revision would then, through Art. 30, always prevail over, for example, regulatory treaties that are not often revised (but may be more important).  It is highly questionable whether this result would still be in line with the underlying rationale of Art. 30, that is, giving preference to the “latest expression of state consent”. 

Finally, it must be pointed out that the notion of “continuing” or “living” treaties, suggested here, is a logical consequence also of the obligation to interpret certain treaties in an “evolutionary” manner (discussed above).  Evolutionary interpretation and the impossibility of putting a singly time-label on the treaty in question go hand in hand.  As Fastenrath put it:

“the adoption of a strictly static interpretation is consistent only with a view that identifies law with the will of a legislator as expressed in a specific law-creating process”.  

Thus, the Appellate Body’s evolutionary approach to treaty interpretation must be matched with an acknowledgement that the WTO treaty is a “continuing” or “living” treaty in respect of which the lex posterior principle in Art. 30 cannot always be applied.

7.	Practical consequences for conflicts involving the WTO treaty as a “continuing treaty”
It should normally be sufficient that one of the two treaty norms in conflict is of a “continuing” or “living” nature for Art. 30 to be dis-applied (i.e., for the treaty norms not to be “successive”).  This would be the case, for example, when two original WTO members conclude a bilateral treaty, addressing certain trade issues, in 2000.  In case of conflict between the two treaties, it would then, indeed, be difficult to say that the two treaties are “successive” in time, since WTO rules existed before the bilateral treaty was concluded and continue to be confirmed after that.  The conflict should then be better solved by, for example, the lex specialis principle, according to which the bilateral treaty would most likely prevail either because of its more specific subject-matter or its more specific membership, or both.  

Nonetheless, even “continuing” or “living” treaties do have a starting point, even if this starting point is not the beginning and the end of state consent to the treaty.  As a result, there may be treaties that were concluded before the starting point of a continuing treaty.  Consequently, there may still be conflicts involving a continuing treaty where the two treaties are “successive” and the continuing treaty prevails as later in time under Art. 30.  For example, the starting point of GATT is 1947.  That of new WTO agreements, 1994.  Thus, in case of a conflict between a GATT 1947/WTO norm and another norm (not of a continuing nature) which clearly pre-dates the GATT 1947/WTO norm (say, a bilateral agreement concluded in, respectively, 1930 or 1980),  Art. 30 should still find application  given that the two treaties are then, indeed, “successive” in time.  Indeed, although the consent to the GATT 1947/WTO norm was given in 1947/1994 and continues to be confirmed thereafter, it remains the case that the (non-continuing) consent given to the other norm pre-dates the consent to the GATT 1947/WTO norm.

However, in the event of conflict between two norms of the “continuing” or “living” type, it seems difficult to apply Art. 30 at all, except in case one norm is an explicit amendment of the other in the sense of Art. 40 VCLT.  Even if the starting point of one of the two treaties may then pre-date that of the other, given that the norms are in conflict, at the time of the conflict both exist and continue to be confirmed at the same time.  Hence, the two treaties cannot be defined as “successive” in time.  They are rather “parallel” in time.  Thus, Art. 30 cannot be applied and, most probably, the lex specialis principle will resolve the conflict.

III.	CONCLUSION

This paper makes two arguments in respect of the nature of WTO obligations.  Firstly, that WTO obligations are bilateral/reciprocal in nature.  Secondly, that WTO obligations and, more generally, WTO treaty provisions, are dynamic in nature and supported by state consent that was not exhausted in 1994 but continues to be confirmed.  If accepted, this approach would have crucial consequences, first of all, within the WTO.  It would restrict the legal standing to bring a complaint before a WTO panel and favour an evolutionary interpretation of WTO treaty provisions.  In addition, the propositions made in this paper weigh heavily on the relationship between WTO law and other rules of international law.  It would, in principle, allow for a limited number of WTO members to deviate from WTO obligations inter se and preclude the application of the lex posterior rule to resolve a number of conflicts between WTO provisions and other treaties.