Australia's Reliance on US Extended Nuclear Deterrence and International Law

Abstract

One of the central tenets of Australia's defence policy is to rely on the extended nuclear deterrence of the United States ("US"). In recent years, politicians and civil society have questioned the doctrine's compatibility with Australia's international legal obligations but to date there has been very little academic analysis of the issue. The lack of scholarship in this area is concerning given that the legality of Australia's reliance on US nuclear protection has significant ramifications for US-Australian relations, Australia's national security policy and the global nuclear disarmament movement more broadly. This article explores the international legal issues that arise with respect to Australia's policy of extended nuclear deterrence. The first part of the article focuses on whether the Australia, New Zealand, United States Security Treaty ("ANZUS") places Australia under US nuclear protection and, if so, whether ANZUS requires Australia to maintain its policy of extended nuclear deterrence. It argues that, as currently interpreted, Article IV of ANZUS implicitly allows for the US to use, or threaten to use, nuclear weapons in defence of Australia. However, contrary to what has been asserted by an Australian politician, this state of affairs does not mean that Australia is under an obligation to maintain its policy of extended nuclear deterrence. Having determined that ANZUS does not prevent Australia from giving up nuclear deterrence, the article then turns to examine whether the Nuclear Non-Proliferation Treaty ("NPT") or the South Pacific Nuclear Free-Zone Treaty ("Treaty of Rarotonga") require Australia to abandon its reliance on US nuclear protection. The article argues that while Australia's policy of extended nuclear deterrence does not conflict with the terms of the Treaty of Rarotonga, Article VI of the NPT creates a more significant challenge for the policy. Article VI of the NPT requires Australia "pursue negotiations in good faith towards effective measures" relating to nuclear disarmament. While this obligation is not necessarily incompatible with extended nuclear deterrence, Australia's entrenched opposition to a global nuclear ban treaty casts doubt on Australia's commitment to the NPT.