Nuclear Nonproliferation Objectives of Permanence with Accountability at Stake: The Role of International Law in the Interlude Between the Tenth and the Eleventh Review Conference of the Parties to the Treaty on the Non-proliferation of Nuclear Weapons

This chapter aims to discuss the meaning and implication, in terms of international law, of the concept of permanence with accountability in the framework of the tenth Review Conference of the States party to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) and in the interval between this and the next Review Conference. After contextualizing the concept of permanence with accountability, which was adopted when the NPT was indefinitely extended in 1995, the chapter investigates whether the decisions on practical measures to implement Article VI of the NPT taken at the 1995, 2000 and 2015 NPT Review Conferences can be regarded as subsequent agreement or subsequent practice to the NPT. Guided by the ‘Draft Conclusions on Subsequent Agreement and Subsequent Practice in Relation to the Interpretation of Treaties’, adopted in 2018 by the United Nations International Law Commission, it is held that (i) Article VI contains an obligation to achieve a precise result by adopting a particular course of conduct, (ii) the fact that a certain result has not been achieved does not necessarily constitute a breach of Article VI, (iii) the question of whether Article VI has been breached should be answered by drawing upon the consensus outcomes of the NPT Review Conferences, (iv) to the extent that these outcome documents have specified obligations to such a level of concreteness that States can take action individually, inaction may amount to noncompliance with Article VI. The concept of permanence with accountability serves as a litmus test, since it has all the objective and subjective prerequisites of fact whose presence is constitutive of a subsequent agreement or subsequent practice. The discoloration achieved under this test, indicating a possible violation of Article VI of the NPT, occurs in cases where, on the one hand, negotiating States have not yet signed or ratified the 1996 Comprehensive Nuclear-Test-Ban Treaty (CTBT), and, on the other hand, nuclear-weapon States frustrate even the most moderate transparency expectations of non-nuclear-weapon States, such as providing relevant and comparable information in a standardized reporting format, on which accountability could be based. It is essentially the responsibility of nuclear-weapon States party to the NPT to provide the NPT treaty regime with the impetus for regime stability which the compatibility of their actions with the concept of permanence with accountability would represent. In an adjacent phase, to be masterminded by cooperative intersessional work leading up to the eleventh Review Conference, it would be the joint responsibility of nuclear-weapon States and non-nuclear-weapon States party to the NPT to lay the ground for a modernization of the treaty regime by reforming it institutionally in the style of other treaty regimes of disarmament and arms control, and thus to overcome the under-complexity of the NPT regime in terms of international law.