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19. Withdrawal from arms control treaties



I. Introduction

II. The law of treaties and withdrawal clauses in arms control treaties

III. Recent examples in state practice

IV. Conclusions


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The role of legally binding agreements in achieving arms control objectives has been the subject of discussion in recent years. One specific aspect, the circumstances in which a state may unilaterally withdraw from its legal obligations, has become especially controversial.


A legally binding agreement under international law—a treaty—is generally seen as a robust tool for the recording of agreements between states. The conclusion, maintenance and termination of such agreements are governed by a branch of international law known as ‘the law of treaties’. The performance of obligations owed under a treaty is safeguarded by the principle expressed in the Latin maxim pacta sunt servanda—agreements are to be honoured in good faith. A central element in the notion of a legally binding agreement is that its termination is subject to the application of legal rules, rather than the discretionary interests of single parties. Subjecting the termination of a treaty to legal rules and principles serves to maintain stability and predictability in international relations.


On 10 January 2003, North Korea revoked a 10-year ‘moratorium’ on its 1993 unilateral withdrawal from the multilateral 1968 Treaty on the Non-Proliferation of Nuclear Weapons (Non-Proliferation Treaty, NPT). In 1993 it had invoked a special clause in the NPT that allows a party, in exercising its national sovereignty, to withdraw from the treaty if it decides that ‘extraordinary events’ have jeopardized its supreme interests. The North Korean withdrawal from the NPT in 2003 was the first instance of such a clause being invoked in relation to a modern multilateral arms control agreement. However, it was not the first instance of a state using a similar clause to renounce obligations owed under an arms control treaty. In 2002, the United States withdrew from the 1972 Treaty on the Limitation of Anti-Ballistic Missile Systems (ABM Treaty), a bilateral agreement between it and the Soviet Union/Russia, by invoking a similar clause on unilateral withdrawal.


The actions taken by the North Korean and US governments are unprecedented in the modern history of international arms control and raise several fundamental and important questions in relation to the role usually attributed to legally binding agreements as a robust tool for arms control. Prima facie, a unilateral withdrawal would seem to run counter to the notion that the termination of a legally binding international agreement should not be at the discretionary interest of a single party. On the other hand, because both the USA and North Korea invoked provisions that were part of the pactum in question, their actions are not contrary to the principle of pacta sunt servanda. However, it should also be emphasized that the context is markedly different in each case. The USA withdrew from the ABM Treaty because its plans for the development of a ballistic missile defence system would have violated the treaty. North Korea, however, invoked the withdrawal clause after having violated its obligations under the NPT.


What effect, if any, these two events might have on future invocations of the extraordinary events clause remains to be seen. In any event, it cannot be said that the requirement to provide an explanation served as a moderating factor in either case. None of the arguments presented by the states concerned in support of the use of the clause is persuasive.


Neither case resulted in any negative consequences for the withdrawing party. This could set a future standard and may in a sense ‘lower the threshold’ for the invocation of this type of withdrawal clause in order to terminate legally binding relationships. This would, in turn, run counter to efforts to obtain stability and predictability in international relations.



Dr Christer Ahlström (Sweden) has been Deputy Director of SIPRI since August 2002. Previously, he served as a Deputy Director in the Swedish Ministry for Foreign Affairs on issues related to disarmament and non-proliferation of weapons of mass destruction. He contributed to the SIPRI Yearbook in 2003.