A.  Introduction

1  Denunciation denotes a unilateral act by which a party seeks to terminate its participation in a treaty (Unilateral Acts of States in International Law). Lawful denunciation of a bilateral treaty (Treaties) terminates it. Although denunciation is also used in relation to a multilateral treaty, the better term is withdrawal. Withdrawal of a party from a multilateral treaty will not normally result in its termination. But, for simplicity, termination will here be used to describe both termination of a bilateral treaty and withdrawal from a multilateral treaty.

2  The termination of treaties is an immensely practical topic, though often neglected by writers. Part V, Arts 42 to 45 and 54 to 64, Vienna Convention on the Law of Treaties (1969) (VCLT) set out the various circumstances in which a treaty can be denounced, terminated, or its operation suspended, other than on the ground of invalidity, which ground is very rarely invoked, and even more rarely successfully (Treaties, Validity). Arts 65 to 72 VCLT specify the procedures to be followed and the consequences of termination or suspension.

3  To be effective, termination or suspension may only take place as a result of the application of the provisions of the treaty itself or the VCLT (Art. 42 (2)). Unless the treaty provides otherwise, it is for the party claiming that a treaty has been terminated or suspended to establish that the necessary grounds exist. Most treaties contain provisions on termination, and termination provisions are usually closely linked to those on the duration of the treaty. The two matters must therefore be considered together.

B.  Express Provisions

4  A treaty, whether bilateral or multilateral, may terminate, or a party may withdraw from it, in conformity with its provisions (Art. 54 (a) VCLT). The following few examples illustrate the great variety of clauses.

C.  No Provision for Termination or Withdrawal

17  Some universal law-making conventions are naturally silent as to their duration, but have provisions for withdrawal, eg the Convention on the Prevention and Punishment of Genocide (1948) (Genocide) and the Geneva Conventions I–IV (1949). Does this mean that when other similar conventions (including the VCLT itself), or other treaties, bilateral or multilateral, are silent as to their duration and have no provision for withdrawal, one cannot imply such a right? Art. 56 (1) VCLT prohibits a party from denouncing or withdrawing unless:

1. (a)  it is established that the parties intended to admit the possibility of denunciation or withdrawal; or

2. (b)  a right of denunciation or withdrawal may be implied by the nature of the treaty.

Since this is expressed as an exception, the onus is on the party wishing to invoke it. Unless another period is established, it must give the other party or parties at least 12 months’ notice of its intention (Art. 56 (2) VCLT).

18  Since it is now very common to include provisions on withdrawal (even for human rights treaties), when a treaty is silent it may be that much harder for a party to establish the grounds for the exception. A party will not be able to withdraw from a treaty transferring territory or establishing a boundary (cf Art. 62 (2) (a) VCLT), except in the (highly unlikely) event of the treaty allowing for this. The same may apply in the case of some codification conventions. Although Art. 317 (1) United Nations Convention on the Law of the Sea (1982) permits denunciation, its predecessors did not (see eg Multilateral Treaties Deposited with the Secretary-General, Ch. XXI.1, Convention on the Territorial Sea and the Contiguous Zone [1958], note 6 regarding the purported denunciation by Senegal). In any event, in many cases the rules in such conventions reflect, or have become accepted as, customary international law, and so withdrawal may make little or no practical difference.

19  Other treaties which are unlikely to be capable of withdrawal are treaties of peace, disarmament treaties, and those establishing permanent regimes, such as for the Suez Canal. Most universal human rights treaties do provide for withdrawal. In the case of the International Covenant on Civil and Political Rights (1966) (‘ICCPR’), the Human Rights Committee (‘the Committee’) established under it has expressed the view in its General Comment 26 that the omission in that case of such a right, as well as the nature of the ICCPR, precludes the existence of the right. In this case the Committee would seem to be right. In August 1997 the DPRK gave notice of withdrawal from the ICCPR. The UN Secretary-General thus informed the DPRK that it could not withdraw unless all the other parties consented. The DPRK appears to have accepted this.

20  Treaties which by their nature are more likely to fall within the exception in Art. 56 (1) VCLT are treaties of alliance, commercial or trading agreements, and cultural relations agreements. The commercial character of a treaty will, however, not be decisive, particularly when the treaty concerns a joint endeavour.

21  Although most of the constitutions of international organizations do not provide for a Member State to withdraw, the right is probably implicit. (see also International Organizations or Institutions, Membership) It will usually be possible to withdraw from a general treaty for the settlement of disputes between the parties even when it has no withdrawal provision. This is consistent with the consensual nature of international jurisdiction: a State can be made subject to the jurisdiction of an international court or tribunal only if it consents, either in advance or ad hoc. (International Courts and Tribunals, Jurisdiction and Admissibility of Interstate Applications) Moreover, States have withdrawn from optional protocols on dispute settlement to several UN treaties (including those associated with human rights treaties) without (at least legal) objection, even when they contain no provision for this. In 2005, the US withdrew from the Optional Protocol to the Vienna Convention on Consular Relations (1963) on the Compulsory Settlement of Disputes. Declarations under Art. 36 of the Statute of the International Court of Justice (ICJ) (Optional Clause, International Court of Justice) can be, and have been, withdrawn. However, the other party or parties will be able to invoke the jurisdiction of the court or tribunal during any period of notice in order to deal with an existing dispute.

22  There may be an inherent time factor conditioning the application of the treaty. Thus, the ICJ rejected the contention of Iceland that it could denounce a treaty with the United Kingdom of 1961 which provided that either party could have recourse to the court if Iceland purported to extend her fishery limits (Fisheries Jurisdiction Cases [United Kingdom v Iceland; Federal Republic of Germany v Iceland]). Since the right to invoke the jurisdiction of the court was deferred until the occurrence of such a well-defined future event, the treaty could not be denounced by Iceland before that event had occurred. ([1973] ICJ Rep 15 paras 25–29)

D.  Termination or Withdrawal by Consent

23  A treaty may of course be terminated, or a party withdraw from it, at any time by consent of all the parties (Art. 62 (2) (b) VCLT). The International Law Commission (ILC) did not accept that the civil law principle of acte contraire (a rule can be altered only by a rule of the same legal nature) applied. The agreement of the parties does not have to be in the same form as the treaty. If the treaty creates rights for a third State in accordance with Art. 36 VCLT, or an obligation has arisen for a third State from the treaty in accordance with Art. 37 VCLT, the consent of the third State may also be needed (Treaties, Third-Party Effect).

24  The treaties between Norway and the UK relating to the exploitation of several oil and gas fields are of indefinite duration and each provide that the two governments ‘may amend or terminate this Agreement at any time by agreement’, so leaving the conditions to be agreed at the time and in the light of the situation then.

E.  Termination or Suspension by Conclusion of a Later Treaty

25  Art. 59 (1) VCLT provides that if all the parties to an earlier treaty are also parties to a later one, and the two treaties relate to the same subject-matter, the earlier treaty will be terminated if:

1. (a)  it appears from the later treaty or is otherwise established that the parties intended that the matter should be governed by that treaty; or

2. (b)  the provisions of the later treaty are so far incompatible with those of the earlier one that the two treaties are not capable of being applied at the same time.

Although a later treaty for a fixed term will not necessarily abrogate an earlier treaty with a longer or indefinite duration, there is likely to be a presumption that the parties intended that effect. The earlier treaty will be considered as only suspended in operation if it appears from the later treaty, or it is otherwise established, that that was the intention of the parties (Art. 59 (2) VCLT).

26  Despite their apparent similarities, Art. 59 VCLT does not cover the same ground as Art. 30 VCLT on successive treaties (Treaties, Conflicts between). The latter is concerned with the application of two or more treaties relating to the same subject-matter, and deals only with the priority of inconsistent obligations in treaties when there is no doubt that both are in force. It therefore comes into play only once it has been determined, by the application of the rules in Art. 59 VCLT, that the parties did not intend to abrogate or suspend the earlier treaty.

F.  Termination or Suspension for Breach

27  Like the violation of any other international obligation, breach of a treaty obligation may entitle another party to terminate or withdraw from the treaty or suspend its operation (Treaties, Suspension). If it causes harm to another party or its nationals, that party may have the right to take reasonable countermeasures, or to present an international claim for compensation or other relief, invoking State responsibility.

G.  Supervening Impossibility of Performance

33  If an object which is ‘indispensable’ for the execution of a treaty disappears permanently or is destroyed, thereby making the performance of the treaty impossible, a party can invoke this as a ground for terminating or withdrawing from the treaty (Art. 61 (1) VCLT). The rule has been much criticized, and there are few precedents. In the Case Concerning the Gabčíkovo-Nagymaros Project (Hungary v Slovakia) (Merits) (Gabčikovo-Nagymaros Case [Hungary v Slovakia]), the ICJ held that the object of the treaty had not definitively ceased to exist, there being in the treaty means by which the parties could negotiate necessary adjustments ([1997] ICJ Rep 3 paras 102–103).

34  The ILC mentioned as possible examples of impossibility of performance the submergence of an island (which global warming may now make a practical possibility), the drying-up of a river (though it may not be permanent), or the destruction of a dam. Another example might be the loss by fire of national treasures which one State has agreed to loan to another. If the impossibility of performance is temporary, it is only ground for suspension.

35  At the end of the Falklands conflict in 1982 (Falkland Islands/Islas Malvinas), the complete loss by enemy action of the tents intended for the prisoners of war (‘POWs’) can be regarded as providing grounds for the temporary suspension of the provision in Art. 22 of the Geneva Convention III (1949) which prohibits the holding of POWs on ships, since that was then the only means of protecting POWs from the notorious Falklands weather.

36  Impossibility of performance may not be invoked by a party if it is the result of a breach by it either of an obligation under the treaty (as was the case with Hungary in the Gabčíkovo-Nagymaros Case) or of any other international obligation owed to any other party to the treaty (Art. 61 (2) VCLT). As the Gabčíkovo-Nagymaros Case made clear, serious financial difficulties would not be enough.

H.  Fundamental Change of Circumstances (Rebus Sic Stantibus)

37  The principle, recognized by domestic law, that a person may no longer be bound by a contract if there has been a fundamental change in the circumstances which existed at the time it was signed (in common law, the doctrine of frustration), has been acknowledged to apply also to treaties (Treaties, Fundamental Change of Circumstances). Because the concept was abused in the past, particularly between the two World Wars, Art. 62 VCLT was drawn in restrictive terms. On the other hand, the ILC did not limit it to treaties with unlimited duration and no termination clause, though the Commission noted that, since most treaties now have either express duration or termination clauses, the scope for invoking the article is more limited.

38  Art. 61 (1) VCLT defines strictly the (cumulative) conditions under which a change of circumstances may be invoked:

1. a)  the change must be of circumstances existing at the time of the conclusion of the treaty;

2. b)  the change must be ‘fundamental’;

3. c)  it must not have been foreseen by the parties (ie when they concluded the treaty);

4. d)  the existence of the circumstances must have constituted ‘an essential basis of the consent of the parties to be bound by the treaty’; and

5. e)  the effect of the change must be ‘radically to transform the extent of the obligations still to be performed under the treaty’.

The application of principle is thus strictly circumscribed. A State may not invoke its own conduct. A change of policy by the government of one party would not be enough unless the effect were to alter fundamentally a circumstance which constituted an essential basis of the consent of the parties to the treaty.

39  The principle has been invoked many times, and recognized by treaties. But so far it has not been applied by an international tribunal, though no tribunal has denied its existence. It was considered by the ICJ in the Fisheries Jurisdiction Case (United Kingdom v Iceland) (Jurisdiction) ([1973] ICJ Rep 3 para. 40), the Court finding the article declaratory of customary international law. In the Gabčíkovo-Nagymaros Case the ICJ rejected Hungary’s argument that profound political changes, diminishing economic viability of a project, progress in environmental knowledge, and the development of new norms of international environmental law, constituted a fundamental change of circumstances. The ICJ emphasized that the stability of treaty relations requires that Art. 62 VCLT be applied only in exceptional cases ([1997] ICJ Rep 7 para. 104).

40  In addition to the strict conditions for the application of the principle, Art 62 (2) VCLT makes two exceptions. First, the principle cannot be invoked if the treaty ‘establishes’ a boundary, that term being used so as to include treaties which cede territory, not merely delimit a boundary. Secondly, the principle cannot be invoked if the fundamental change is the result of a breach by the party invoking it of either an obligation under the treaty or any other international obligation owed to any other party to the treaty. This is an application of the general principle of law (General Principles of Law) that a person cannot take advantage of his or her own wrongdoing, which is applicable to any of the grounds for termination which might be invoked. It is mentioned here, and in Art. 61 VCLT (impossibility of performance), because of the risk that the grounds dealt with by them might well result from a breach of treaty.

41  There is also a case for saying that a party to a human rights treaty, which does not have a right of denunciation provision, though its Optional Protocol on dispute settlement does, cannot withdraw from it unilaterally. In the case of the ICCPR, the Human Rights Committee established under it has expressed its view that the omission of such a right, as well as the nature of the Covenant, precludes the existence of the right (General Comment No 26 (61), [1995] ILM 839). Although the views of the Committee are not determinative of the matter, and sometimes must be treated with caution, in this case they would seem to be correct. Following the decision of the Inter-American Court of Human Rights (IACtHR) in Baruch Ivcher-Bronstein v Peru (Case 11.76, judgment 20/98), Peru purported to denounce the American Convention on Human Rights (1969), but later withdrew the denunciation.

I.  Severance of Diplomatic or Consular Relations

42  The severance of diplomatic or consular relations between parties to a treaty does not affect the legal relations established between them by the treaty, except in so far as the existence of diplomatic or consular relations is indispensable for the application of the treaty (Art. 63 VCLT). (Diplomatic Relations, Establishment and Severance) The rule applies both to bilateral and multilateral treaties. Diplomatic relations between Iraq and the UK were broken off in 1990 following the invasion of Kuwait. Nevertheless, between then and 2002 Iraq applied at least three times under the Iraq-UK Extradition Treaty 1932 for the extradition of Iraqi nationals, the applications and responses being transmitted through third States. Each application was refused, but not on the basis that the Treaty was suspended. (See also War, Effect on Treaties)

J.  Other Grounds for Termination

43  The ILC has been criticized for excluding from the draft Convention other suggested grounds of termination. However, those usually mentioned may not really be grounds for termination. They include the following.

K.  Procedure

47  The ILC was concerned that the grounds for termination or suspension might be invoked as a pretext for casting off inconvenient treaty obligations. The danger for the security of treaties is particularly great if the ground invoked is based on an alleged material breach or fundamental change of circumstances, both of which can produce a substantial degree of subjectivity. Art. 65 VCLT is thus a key provision, its procedural safeguards being designed to deter States from arbitrary action, though it is often ignored. In the Gabčíkovo-Nagymaros Case ([1997] ICJ Rep 7 paras 108–110) the ICJ recognized that Treaties, Validity) Arts 65–67 VCLT generally reflected customary international law and contain certain procedural principles which are based on the obligation to act in good faith (bona fide).

L.  Consequences of Termination, Withdrawal, or Suspension

48  Art. 70 VCLT does not deal with any question of State responsibility if, for example, a treaty has been terminated because of the breach of it by another party; and many treaties, including law-making treaties, do not contain provisions on the consequences of termination. But a treaty, whether bilateral or multilateral, pursuant to which acts are likely to be taking place at and after termination may, as the opening words of Art. 70 (1) VCLT recognize, have transitional provisions applying the treaty in whole or in part to such acts even after termination. Thus, Art. 65 European Convention for the Protection of Human Rights and Fundamental Freedoms (1950) provides that denunciation shall not release a party from its obligations in respect of any acts which, being capable of constituting a violation of those obligations, may have been done before the denunciation becomes effective. The same will apply to treaties on the settlement of disputes. Transitional provisions are especially important when the treaty deals with a project which involves joint financing. Such provisions have to be tailor-made to suit the circumstances of the particular treaty, and can be complex.

M.  Miscellaneous