This article analyses whether Articles I and II of the Nuclear Non-Proliferation Treaty (NPT) permit nuclear sharing. It argues—contrary to previous research—that the ordinary meaning of Articles I and II, the NPT’s travaux préparatoires and subsequent agreements and practice point to a deep ambiguity as to whether nuclear sharing is permitted under these Articles. It then suggests that, while Articles I and II NPT offer little help in determining the legality of nuclear sharing, the nuclear disarmament obligation embedded in Article VI NPT can be used to challenge the legality of the practice.

This paper argues that pursuing negotiations in good faith on effective measures for nuclear disarmament is a legal obligation, not a foreign policy option. Drawing on the New Agenda Coalition paper of April 2014, which identified some pathways by which nuclear disarmament might be pursued, this paper identifies and analyzes international legal issues raised by each of those pathways. The paper concludes by explaining why legal analysis and discussion are important even in the absence of a settled political commitment to nuclear disarmament.