- State practice — General principles of international law — Unilateral acts — Vienna Convention on the Law of Treaties — Treaties, invalidity, termination, suspension, withdrawal — Treaties, amendments and modification — Treaties, successive
Published under the auspices of the Max Planck Foundation for International Peace and the Rule of Law under the direction of Rüdiger Wolfrum.
1 Suspension of a treaty (Treaties) means the temporary cessation of the operation of all or of a part of a treaty. The effect of suspension, according to Art. 72 Vienna Convention on the Law of Treaties (1969) (‘VCLT’) is that the suspending parties are released from the obligation to perform the treaty in their mutual relations during the period of the suspension. However, the suspension does not otherwise affect the legal relations between the parties which have already been established by the treaty. Suspension presupposes the continued existence of the treaty: Art. 72 VCLT provides that it is the operation of the treaty, or part of it, which is suspended, not the treaty itself. The effect thus differs from termination (Treaties, Termination) which, if valid, brings the treaty itself to an end. Nor does suspension as such alter the provisions of the treaty, although the suspension of a part of it can have the effect of modifying the parties’ obligations under the treaty as a whole. (Treaties, Amendment and Revision) Suspension of a treaty does not annul or suspend whatever jurisdictional clauses (see also Arbitration; Judicial Settlement of International Disputes) might exist in the treaty (see Appeal Relating to the Jurisdiction of the ICAO Council [Judgment]  ICJ Rep 46 para. 32; International Civil Aviation Organization, Jurisdiction of, Case). A party to a treaty cannot absolve itself through suspension of the treaty of an obligation which also exists by virtue of customary international law (see also Case concerning Military and Paramilitary activities in and against Nicaragua [Merits]  ICJ Rep 14 para. 178). Military and Paramilitary Activities in and against Nicaragua Case [Nicaragua v United States of America]
2 Both multilateral and bilateral treaties can be suspended. Depending on the circumstances, suspension can be an agreed act, taken by all the parties to a treaty; a collective act by a number of parties; or a unilateral act by one party. (Unilateral Acts of States in International Law; see also Unilateralism/Multilateralism) Where it is a unilateral or non-consensual collective act, suspension will usually be employed as a method of bringing pressure on another party or parties, and, as such, will often be intended to restore the equilibrium of a treaty disrupted by a breach. As the treaty is supposed to resume operation as soon as the grounds for suspension have ceased to apply, Art. 72 VCLT provides that during the period of the suspension the parties shall refrain from acts tending to obstruct the resumption of the operation of the treaty. Unless otherwise provided for by the treaty, a unilateral suspension may be revoked, and the treaty reactivated by the suspending party acting alone.
3 Which organ of a State (States) is entitled to suspend the operation of a treaty depends upon national law (International Law and Domestic [Municipal] Law ; Treaty Making Power). Constitutional requirements—eg of parliamentary consultation/consent—which may exist may be less onerous as regards executive suspension of treaties as compared to executive termination of treaties (see eg Prefect of La Gironde v Mahmedi Conseil d’Etat [Council of State] Paris 18 December 1992, 106 ILR 204).
4 Suspension of a party to a treaty is governed by the terms of the treaty in question (Art. 57 (a) VCLT). Treaties which contain clauses allowing certain provisions to be suspended unilaterally subject to certain conditions include human rights treaties, disarmament treaties—eg Art. 29 (4) Treaty of Tlatelolco—and association/trade treaties —eg Art. 96 Cotonou Agreement which provides for suspension as a measure of ‘last resort’. (see also Commercial Treaties; Lomé/Cotonou Conventions; Treaties of Friendship, Commerce and Navigation) Dispute settlement provisions may apply when one party purports to suspend a treaty but, failing these, the legality of a unilaterally implemented suspension will not be authoritatively determined. Suspension of membership of an international organization (International Organizations or Institutions, Membership) involves the suspension, for a State Party, of the privileges of membership in accordance with the statute of the organization. However, this involves different considerations from other cases of treaty suspension and should be seen as a separate subject. The same applies to suspension of an international contract (see eg Klöckner Industrie-Anlagen GmbH v United Republic of Cameroon ICSID Case No ARB/81/2 (1994) 2 ICSID Rep 9 (excerpts). Contracts between States and Foreign Private Law Persons; see also Contracts between International Organizations and Private Law Persons)
5 Where a treaty contains no suspension clause, it may still be capable of being suspended in accordance with general principles of international law. (General Principles of Law) Art. 42 VCLT provides that suspension of the operation of a treaty may take place only as a result of the application of the provisions of the treaty or of the VCLT. Where suspension is not permissible, it will constitute a breach of the treaty.
6 Apart from Art. 57 (a), the VCLT recognizes six different situations in which suspension can occur. Similar situations apply for international organizations under the Vienna Convention on the Law of Treaties between States and International Organizations or between International Organizations (International Organizations or Institutions, External Relations and Co-operation). The first situation is under Art. 57 (b) VCLT, suspension by the consent of all the parties. This is subject to the condition that the parties consult even with the other contracting States which have not yet become parties. An example of such a suspension may be found in International Coffee Council resolution 347 of 3 July 1989 suspending certain provisions of the International Coffee Agreement. (Commodities, International Regulation of Production and Trade) Although the wording of Art. 57 (b) VCLT indicates that the suspension must be of the whole treaty, suspension of a part of it is also possible (see Commentary to Art. 54 UN ILC ‘Draft Articles on the Law of Treaties with Commentaries’  [‘ILC Draft Articles LT’]), notwithstanding the provisions in Art. 44 (1) VCLT relating to separability. The second situation is under Art. 58 VCLT where two or more parties to a treaty agree to suspend the operation of its provisions temporarily and as between themselves. The rule on suspension by certain parties only resembles the rule in Art. 41 VCLT on modification, and similar limitations and safeguards apply such as reasonable notice, etc. Either this possibility must be provided for by the treaty or it must not be prohibited by it. In the latter case, the suspension must not affect the enjoyment by other parties of their rights under the treaty or the performance of their obligations, and the suspension must not be incompatible with the object and purpose of the treaty (Treaties, Object and Purpose). As mentioned, while suspension should be distinguished from both amendment as regards Art. 40 VCLT and modification as regards Art. 41 VCLT, in practice it can have similar legal effects.
7 The remaining situations—Arts 59 to 62 VCLT—are grounds which may be invoked for both termination and suspension. However, under certain conditions, only suspension is possible. The treaty is not suspended automatically: a party must invoke a ground for suspension first. Nor does the mere invocation mean that the treaty can be suspended: Arts 65 to 68 VCLT lay down procedural safeguards such as notification, etc to be applied when a party invokes these grounds in order to suspend a legally binding relationship. A right to invoke a ground for suspension can also be lost through passivity (Art. 45 VCLT; see also Acquiescence; Tacit Consent). The third situation is where all the parties to a multilateral treaty, without expressly terminating an earlier treaty, enter into another and incompatible treaty on the same subject (Treaties, Conflicts between). This can be solved either by suspension under Art. 59 VCLT or by means of the rule in Art. 30 VCLT whereby the earlier treaty is to be interpreted as only being applicable to the extent that it is not in conflict with the later treaty (Interpretation in International Law), which will usually amount to suspension in practice (Commentary to Art. 56 ILC Draft Articles LT para. 1). For an example of a case which arguably should have been solved in this way see RD v Belgian Government Cour de Cassation [Supreme Court of Justice] Belgium 24 August 2004, Oxford Reports on International Law in Domestic Courts 6 (BE 2004).
8 The fourth situation is material breach. First, under Art. 60 (2) (a) VCLT, following a material breach by one party, there is a right for all the other States Parties, acting unanimously, to suspend a treaty in whole or in part, either as between themselves and the defaulting State, or as between all the parties. Here, unlike for Art. 60 (2) (b) and (c) VCLT, all the other parties need only agree that a party has materially breached the treaty: it is not necessary to proceed to a determination that a breach has actually occurred. Secondly, a party specially affected by the breach may invoke it as a ground for suspending, not terminating, the operation of the treaty in whole or in part in the relations between itself and the defaulting State (Art. 60 (2) (b) VCLT). There was some discussion in the International Law Commission (ILC) as to whether suspension should be possible at all for multilateral law-making treaties. However, the position was eventually taken that, since multilateral treaties tend to function primarily through bilateral relations between the parties, it would be inequitable not to allow suspension. Suspension was considered to be sufficient to safeguard a specially affected party’s interests. Finally, any party other than the defaulting State may invoke the breach as a ground for suspending the operation of the treaty where a material breach ‘radically changes the position of every party with respect to the further performance of its obligations under the treaty’ (Art. 60 (2) (c) VCLT). The ILC intended this case to apply to treaties such as disarmament agreements. Although only part of the treaty may be suspended under Art. 60 (2) (c), as with Art. 60 (2) (a) and (b) VCLT, the fact that the breach must radically change the position of all the parties means that they are unlikely to choose the remedy of partial suspension. According to Art. 60 (3) VCLT, the above rules are subject to the exception that humanitarian treaties may not be suspended. (Humanitarian Law, International)
9 Suspension for breach cannot be exercised pre-emptively: a material breach must have actually occurred. Only a breach of the treaty in question entitles another party to suspend the treaty or part of it (Case concerning the Gabčíkovo-Nagymaros Project [Hungary/Slovakia] [‘Gabčíkovo-Nagymaros Case’] para. 106; Gabčíkovo-Nagymaros Case [Hungary/Slovakia]). Although suspension is a less radical remedy than termination, the ILC did not distinguish between the degree of ‘materialness’ in the breach for the invocation of the two remedies. Suspension as a remedy to a breach does not cancel the breach: other remedies (Reparations) will continue to be available, even if the right to suspend is waived.
10 The fifth situation is supervening impossibility. Art. 61 (1) VCLT provides that if the impossibility results from the temporary disappearance or destruction of an object indispensable for the execution of the treaty, the treaty may be suspended. The sixth and final situation is that of Art. 62 VCLT, a fundamental change of circumstances (clausula rebus sic stantibus; Treaties, Fundamental Change of Circumstances) that may also serve as a ground for suspending performance of a treaty (see eg the already mentioned case Prefect of La Gironde v Mahmedi). The same conditions apply as for the invocation of this ground for terminating or withdrawing from the treaty. For both supervening impossibility and fundamental change of circumstances, and unlike the situation for material breach, it is not possible to suspend simply part of the treaty. The International Court of Justice (ICJ) considers that the provisions on suspension and termination in Arts 60 to 62 reflect customary international law (Gabčíkovo-Nagymaros Case para. 46).
C. Other Situations in which Suspension Can Arise and Concluding Remarks
11 There are a number of other situations in which treaties can be suspended. Member States of the United Nations (UN) are obliged to carry out United Nations Security Council sanctions adopted under Chapter VII United Nations Charter; Art. 25 UN Charter; United Nations, Security Council), and obligations under the UN Charter have precedence over other treaty obligations (Art. 103 UN Charter). This means, inter alia, that treaty obligations can be suspended. For example, a treaty providing for freedom from visa requirements can be suspended during the period of travel sanctions imposed on government officials. Under the Vienna Convention on Succession of States in Respect of Treaties (‘VCSS-T’; State Succession in Treaties; see also State Succession in Other Matters than Treaties), for a newly independent State, the operation of a treaty binding upon the predecessor State is suspended pending the former’s notification of succession (Art. 23 VCSS-T). Where a predecessor State has suspended the operation of a treaty, this does not prevent the treaty from being in operation between a newly independent State and the other parties, if they so agree (Art. 26 VCLT). The effect of armed conflict on treaties was deliberately excluded from the scope of the VCLT (Art. 73 VCLT) and is currently under consideration by the ILC. (Armed Conflict, Effect on Treaties; Armed Conflict, International) The basic approach taken by the ILC rapporteur so far has been that armed conflict does not of itself suspend treaties, and that the susceptibility of the treaty in question to suspension (or termination) has to be assessed in accordance with the intentions of the parties and the nature and extent of the conflict in question. It should be noted that severance of diplomatic relations does not, in itself, suspend treaties (Art. 63 VCLT). Diplomatic Relations, Establishment and Severance
12 As mentioned, suspension can be a means for one party to put pressure on another party. As such, older doctrine often treated suspension as falling within the law of State responsibility. The ICJ has, however, now made it clear that the determination of whether a convention has been properly suspended is to be made pursuant to the law of treaties (Gabčíkovo-Nagymaros Case para. 47). However, a party to a treaty is also entitled to invoke a circumstance precluding wrongfulness in order to excuse a suspension which would otherwise be a breach of the treaty (Gabčíkovo-Nagymaros Case paras 47 and 101). Although practice is relatively scarce, (State Practice) States have, collectively or unilaterally, invoked suspension of a treaty as a countermeasure (Countermeasures) to a prior breach of international law (Case Concerning the Air Services Agreement of 27 March 1946 [United States of America v France] (1979) 18 RIAA 416), eg various States suspended air traffic agreements with the Soviet Union following the shooting down of a South Korean civil airliner in 1983. (Korean Air Lines Incident ) The preponderant view is that the substantive conditions, as well as the procedural requirements, laid down by the VCLT do not apply to such provisional suspension or non-performance. Instead, the lawfulness of this, being a countermeasure, falls to be judged under the law of State responsibility.
13 Suspension is relatively rare in international law. It can, however, be assumed that the threat of suspension of a treaty has occasionally served to re-establish compliance with a treaty. Treaties which allow the parties a degree of flexibility in how they perform the treaty, or which obligations they undertake in the treaty, will tend to reduce the need for suspension, as do treaties which provide for monitoring and other preventive mechanisms for ensuring compliance.
- G Richard ‘KAL 007: The Legal Fallout’ (1984) 9 AnnAir&SpaceL 47–61.
- I Sinclair, The Vienna Convention of the Law of Treaties (Manchester University Press Manchester 1984).
- FL Kirgis ‘Some Lingering Questions about Article 60 of the Vienna Convention on the Law of Treaties’ (1989) 22 CornellIntlLJ 549–73.
- LH Sicilianos ‘The Relationship between Reprisals and Denunciation or Suspension of a Treaty’ (1993) 4 EJIL 341–59.
- P Reuter, Introduction au droit des traités (P Cahier (ed), 3rd ed Presses Universitaires de France Paris 1995).
- MM Gomaa, Suspension or Termination of Treaties on Grounds of Breach (Nijhoff The Hague 1996).
- A Aust, Modern Treaty Law and Practice (CUP Cambridge 2000).
- C Feist, Kündigung, Rücktritt und Suspendierung von multilateralen Verträgen (Duncker & Humblot Berlin 2001).
- American Law Institute Restatement of the Law Third: The Foreign Relations Law of the United States (American Law Institute Publishers St Paul 1987) vol 1 §§ 1–488 §§ 333–39.
- Case concerning the Gabčíkovo-Nagymaros Project (Hungary/Slovakia) (Judgment)  ICJ Rep 7.
- UN ILC ‘Draft Articles on the Law of Treaties and Commentaries’ (1966) GAOR 21st Session Supp 9, 20.
- Vienna Convention on Succession of States in Respect of Treaties (with Annex) (concluded 23 August 1978, entered into force 6 November 1996) 1946 UNTS 3.
- Vienna Convention on the Law of Treaties (with Annex) (concluded 23 May 1969, entered into force 27 January 1980) 1155 UNTS 331.