Policy Brief 26 - Asia–Pacific Strategic Nuclear Policy Dialogues 1: The United States and Its Allies

  • Jan 25, 2017


Strategic nuclear competition is on the rise in the Asia Pacific. In response, as was the case in Europe during the Cold War, dialogue has developed, slowly but steadily, between key players. Today it is most developed between the United States and its Asian allies, notably between the United States and Japan and the United States and South Korea, where much progress has been made in recent years. There is still considerable scope for enhancement, however, as well as opportunities to launch new processes involving Australia. This is the focus of this paper, while its companion will explore the dialogues currently in place, developing or desired with/between the Asia–Pacific’s four nuclear-armed states: China, India, Pakistan and North Korea.

1. Lawrence Freedman once observed that nuclear deterrence theory “is a gift to strategists in that its nature and workings remain so elusive and so imperfectly understood as to permit endless speculations with little danger of empirical refutation.”[1]  While true, there is an important downside to this “gift”: failing to reach common understandings with friends and foes on policy could have highly destabilizing, even devastating consequences. As a result, it is important to formulate and implement deterrence policy or, as it has come to be understood in its broadest sense, “strategic nuclear policy,” in tandem with in-depth dialogue with relevant parties.[2] 

2. This paper is the first of two that analyse strategic nuclear policy dialogues (SNPD) in the Asia–Pacific. This first paper begins with a review of the origins and evolution of SNPD as a process, which has its roots in Europe and only started to develop in the Asia–Pacific in recent years (and to this day remains in its infancy and mostly active at the track-2 and 1.5 levels).[3]  It then moves on to explore the state of play between the United States and its Asian allies and partners. The second paper will, in turn, look at the specific types of SNPD in place, developing or desired with the region’s four nuclear-armed states: China, India, Pakistan and North Korea.[4] 

Strategic Nuclear Policy Dialogues: Origins and Evolution

3. The tradition of SNPD dates back to the early years of the nuclear revolution and Cold War. Because of the realities of the US–dominated, Eurocentric security environment at the time (and because the United States had just fought the Second World War with a Europe-first strategy), SNPD developed with Europe as its focus. It developed in two directions: between the United States and its allies of the North Atlantic Treaty Organization (NATO), and between the United States and its bitter adversary, the Soviet Union, with which the risks of war were highest on the European continent. 

4. In addition to acting as an assurance mechanism, the goal of SNPD between the United States and its NATO allies, still in place today, has been to discuss their shared roles and responsibilities in nuclear planning and operations to deter and, if necessary, fight a war against the Soviet Union and, after the Cold War, Russia. In the NATO model, the nuclear forces of its three nuclear weapon states (the United States, United King-dom and France) provide the “supreme guarantee” of the security of all allies, while a sub-group of other allies participate in the Alliance’s unique sharing arrangements, whereby the United States forward-deploys nuclear weapons and together with these allies operates dual-capable aircraft. As NATO’s senior body on nuclear matters since its creation in 1966, the Nuclear Planning Group brings together the defence ministers of all NATO member states except France and discusses issues related to nuclear forces, planning and operations. These issues are under constant review and are modified in light of developments in the security environment. 

5. SNPD between the United States and the Soviet Union/Russia developed in the context of bilateral arms control discussions. After they built the nuclear capabilities to assure their mutual destruction and after the Berlin and Cuban crises of 1961 and 1962 when they flirted with nuclear confrontation, the United States and the Soviet Union sought to stabilize their relationship by preserving mutual deterrence. This was achieved through arms control negotiations, which began in the early 1960s and first culminated with the conclusion of a “Hot Line” agreement in 1963. This agreement created a direct communication link between Washington and Moscow for use in time of emergency. It was followed by several rounds of negotiations that led to agreements imposing limits and, later, reductions on US–Soviet/Russian nuclear arsenals.[5]  US–Soviet/Russian arms control discussions created de facto SNPD, which in the late 1990s expanded into the NATO context. Under the auspices of the NATO–Russia Council, the United States and Russia have been exploring the requirements of strategic stability in an ongoing dialogue as well as working to improve the relationship between the West and Russia.

6. SNPD between the United States and its NATO allies and between the United States and the Soviet Union/Russia has helped participating states not only better understand, formulate and implement strategic nuclear policy, but also develop habits of cooperation among themselves, thereby improving trust and reducing nuclear dangers.

Developments in Asia

7. Similar developments did not take place in Asia. Even though the United States has been an Asia–Pacific nation for much of its existence, there is no tradition of SNPD in that region, be it between the United States and its Asian allies or between the United States and the region’s increasingly dominant power, China. Despite a US forward nuclear presence – terminated in 1991 – in three Asian allies/partners (the Philippines, South Korea and Taiwan) during much of the Cold War, no robust SNPD emerged or became institutionalized.[6]  Unlike European allies, Asian allies/partners have traditionally remained on the receiving end of US strategic nuclear policy: they have merely relied on a US promise to shield them under the “nuclear umbrella” without explicitly discussing the details of that policy, let alone taking active roles and responsibilities in it. 

8. The absence of a tradition of SNPD between the United States and its Asian allies is partly the result of the lesser importance of Asia during the Cold War. Plainly, at the time, the region was a second-order priority in comparison to Europe and there were therefore less urgent matters to discuss. The primary reason for the absence of SNPD, however, was that the US alliance system in Asia was not designed for dialogue. Unlike Europe, where US defence commitments have been exercised mostly through NATO, a multilateral regional mechanism conducive to dialogue, Washington opted to conclude bilateral defence treaties with its Asian allies to exert maximum control over them, fearing that their anti-communist leaders might engage in aggressive behaviour against adversaries that could trap the United States in an unwanted war.[7]  The United States was considerably more wary of Asian states because none had been longstanding allies, unlike European states.

9. To be fair, there were attempts to establish multilateral defence arrangements in Asia. They all proved unsuccessful, however: the 1951 trilateral Australia, New Zealand, United States Security Treaty (known as ANZUS) dissolved in its original form when New Zealand was suspended in 1986 after initiating a nuclear-free zone in its territorial waters, and the 1954 Southeast Asia Treaty Organization, or SEATO, never gained momentum because internal conflict hindered general use of a common military force.[8]  The alliance system that remained, famously labelled the “hub-and-spokes” system by John Foster Dulles (with the United States as the “hub”), sought not only to contain the Soviet threat, but also to constrain Asian allies, not to engage in dialogue with them, conditions that, obviously, did not produce a fertile environment for SNPD development.

10. Similarly, there is no tradition of SNPD between the United States and China. Unlike in the US–Soviet Union/Russia context, there is no – and has never been any – US–China arms control relationship or bilateral dialogue on strategic nuclear policy. As one analyst has put it, China was “little more than a footnote in the history of the nuclear era.”[9]  The United States overlooked China during most of the Cold War because its priority was the Soviet Union and, in the 1990s, Russia. China was largely “ignored” because, back then, it had a small and mostly unsophisticated nuclear (and conventional) force, especially in comparison to the Soviet Union and then Russia’s.

11. The collapse of the Soviet Union and the end of the Cold War did not immediately lead to SNPD development in Asia. On the contrary: the interest in strategic nuclear policy, including in the United States and Europe, receded in the 1990s because the risks of nuclear war dropped significantly. 

12. To be sure, several nuclear-focused dialogues emerged in Asia since the end of the Cold War, initially at the track-2 and 1.5 levels. Yet none focused on strategic nuclear policy. Instead, they have dealt with non-proliferation, the peaceful uses of nuclear technology, disarmament and, in more recent years (notably after the launch in 2010 of the Nuclear Security Summit process and the 2011 Fukushima nuclear accident in Japan), nuclear safety and security. These issues became central to international security discussions in the context of rising proliferation concerns and mounting worries after the attacks of 11 September 2001 that terrorists might get their hands on nuclear or other weapons of mass destruction and use them. As a result, the Regional Forum of the Association of Southeast Asian Nations (ASEAN) established in 2009 an annual Non-proliferation and Disarmament Inter-sessional Meeting, which track-2 and 1.5 forums, notably the Council for Security Cooperation in the Asia–Pacific, have actively supported. Another example is the launch in 2011 of the ASEAN Network of Regulatory Bodies on Atomic Energy, or ASEANTOM, which enables Southeast Asian regulators to share information and build capacity on nuclear safety, security and safe-guards. Aided by these dialogues and others, much progress has been made in these areas, well beyond the goals of the South Pacific and Southeast Asian nuclear-weapon-free zones, which were concluded in 1985 and 1995, respectively. 

13. From the late 1990s, however, the deteriorating Asian security environment began to provide a growing rationale for SNPD development in the region. By 1998, it became clear that several states across Asia, notably India, Pakistan and North Korea, were developing nuclear and long-range missile programs, while others (China) were working hard to improve existing capabilities. Developments were so significant that analysts began to explain that the epicentre of nuclear politics would soon shift from Europe to Asia. As one scholar pointed out in 2000, “the nuclear future will be written in Asia.”[10]  This became a key feature of the so-called “Second Nuclear Age.”[11] 

14. The early twenty-first century confirmed this trend. Over the past decade and a half, India and Pakistan have developed sophisticated nuclear arsenals, North Korea has become a de facto nuclear-armed state (after conducting numerous missile test-launches and no less than five nuclear tests), and China has pressed on with the development of increasingly modern nuclear and conventional forces. More concerning, and as detailed in more depth later, while the Cold War threat of global nuclear annihilation has not come back, tensions have risen considerably and several serious crises and incidents have erupted, not only between India and Pakistan and between India and China (as will be detailed at length in the second paper), but also between the United States (along with its allies and others) and North Korea and between them and China, all of which ran the risk of nuclear use. While the Ukrainian crisis of 2014 and the conclusion of a nuclear agreement with Iran in 2015 have again begun to raise fundamental strategic nuclear policy questions in both Europe and the Middle East, Asia remains an essential piece of today’s nuclear puzzle, where much of the global nuclear balance lies and will continue to lie in the foreseeable future.

15. In response to these developments, SNPD slowly began to emerge in Asia. Many of these processes, however, remain either in their infancy or mostly active at the track-2 and 1.5 levels. They are most developed between the United States and its Asian allies.

The United States and its Asian allies

16. SNPD between the United States and its Asian allies, by definition, can only take place with allies with whom Washington has a strategic nuclear relationship, that is, with allies it shields under its nuclear umbrella (unlike in Europe, Washington does not have nuclear-armed allies in Asia). While the United States offers security guarantees to its five Asian allies (Australia, Japan, the Philippines, South Korea and Thailand) and has unique obligations with Taiwan, these guarantees do not automatically translate into nuclear umbrella guarantees. Unlike in Europe, where nuclear umbrella guarantees are codified in NATO’s Strategic Concept and rooted in longstanding military and diplomatic practices, the situation is different in Asia. None of the five alliance documents includes such guarantees and while the United States has offered them to some of its Asian allies, it has not done so to others.[12] 

17. Which are the Asian allies shielded by the US nuclear umbrella? Japan and South Korea have such guarantees. Since the conclusion of their alliance with the United States, respectively in 1951 and 1953, Japanese and South Korean officials have been seeking constant assurances that the US nuclear umbrella is in operation, and US officials have always publicly and privately confirmed that it is. For instance, after North Korea’s latest nuclear test last September and mounting worries in Tokyo and Seoul, US President Obama reaffirmed the “unshakable US commitment” to defend Japan and South Korea with “the full spectrum of US defence capabilities.”[13]  Similarly, owing to Australian policy documents and statements, there is a general understanding among Australian and US policymakers that Australia is, and always has been, shielded by the US nuclear umbrella, even in the absence of any US official statement providing that assurance.[14]  According to the 2016 Australian Defence White Paper, for instance, “Only the nuclear and conventional military capabilities of the United States can offer effective deterrence against the possibility of nuclear threats against Australia.”[15]  This is a statement that, like similar ones previously, the United States has not contested (and therefore tacitly endorsed).

18. Neither the Philippines nor Thailand, however, falls under the US nuclear umbrella. There are no official statements suggesting that they do, nor any general understanding among US and Filipino/Thai officials. Significantly, while the United States has formal mutual defence arrangements with the Philippines (as is the case with Japan, South Korea and Australia), it does not have any with Thailand: the US–Thailand alliance only rests on two historic documents, the 1954 SEATO Manila Pact and the 1962 Than-at–Rusk communiqué, neither of which offers a framework for regular review and negotiation.[16]  The United States also does not offer nuclear umbrella guarantees to Taiwan. The 1979 Taiwan Relations Act solely obligates the United States to sell Taipei sufficient arms for its own defence and indicates that efforts to determine the island’s future by non-peaceful means will be considered a threat to the region and of “grave concern” to Washington.[17]  

19. To be clear: the absence of US nuclear umbrella guarantees for the Philippines, Thailand and Taiwan does not mean that Washington does not extend any form of assurance to them. With the Philippines, for instance, Washington has vowed to increase rotational presence of US forces and build maritime capacity amid rising tensions in the South China Sea.[18]  This also does not mean that Washington does not de facto pro-tect these powers with its nuclear umbrella. The mere existence of US nuclear weapons suggests that Washington could get into a nuclear confrontation with an adversary over any Asian ally or Taiwan. Yet what the absence of such guarantees does mean is that the US nuclear umbrella is not on the agenda of discussions with these powers.[19] 

20. Accordingly, SNPD is solely possible between the United States and Japan, South Korea, or Australia. While until recently, as mentioned earlier, no dedicated dialogue was in place, this began to change with the deterioration of the Asian security environment in the 2000s and growing concerns from Washington’s most vulnerable allies: Japan and South Korea. 

Japan and South Korea

21. In the context of the revision of its nuclear policy and capabilities (and its broader “rebalance” to Asia), the United States established in 2010 bilateral SNPD dialogues with Japan and South Korea: the US–Japan Extended Deterrence Dialogue and the US–South Korea Extended Deterrence Policy Committee, later renamed the Deterrence Strategy Committee.[20]  Given the deterioration of the regional security environment, Washington assessed that placing faith in the status quo would likely create problems. Japan and South Korea could decide to bandwagon with US regional competitors or develop nuclear arsenals – a distinct possibility given that both countries considered it in the past, have the capabilities to do so, and some influential people, notably in South Korea, have been increasingly calling for it.[21]  In either case, the credibility of the United States as a security guarantor for the region would plummet (and in the latter case a proliferation cascade could unfold).

22. The Extended Deterrence Dialogue and Deterrence Strategy Committee, which grew out of successful track-1.5 work by the Pacific Forum, a program of the Washington-based Center for Strategic and International Studies (CSIS), have sought to create platforms to feel the pulse of the alliances and improve the assurance of Japan and South Korea by giving them a greater sense of enfranchisement in matters involving their security.[22]  They have also aimed to get them to take on a greater share of the deterrence and defence burden, an important US goal in an increasingly fiscally-constrained environment and in a context where the threats are mostly at the low end of the conflict spectrum, not at the high/nuclear end as during the Cold War.[23]  

23. Both the Extended Deterrence Dialogue and Deterrence Strategy Committee are biannual dialogues, with one of the meetings involving a visit to a site relevant to deterrence.[24]  For instance, the 2013 Extended Deterrence Dialogue visit included a tour of Naval Base Kitsap in Washington State to see the submarine leg of the US nuclear triad and Trident missile facilities, while the 2014 visit took participants to nuclear-related sites at Sandia National Laboratories in New Mexico. Site visits intend to show that US nuclear declaratory policy is backed by demonstrable capabilities. They make US nuclear umbrella guarantees visible and tangible to Japanese and South Korean officials and highlight the hu-man capital and investments at work to keep US capabilities safe, secure and effective. This checks important assurance boxes for Tokyo and Seoul. 

24. Moreover, and significantly, the Extended Deterrence Dialogue and Deterrence Strategy Committee include in-depth, operationally-focused conversations between knowledgeable officials on both sides about current and emerging nuclear threats facing the alliances as well as ways to deter, defend against and respond to them. The Extended Deterrence Dialogue and Deterrence Strategy Committee are not talk shops or mere photo-opportunities. They conduct a joint exploration of the threat environment and the potential responses to it, including though the conduct of table-top exercises. Specifically, they seek to strengthen deterrence by better integrating the policies and capabilities of the United States and Japan/South Korea in a single strategy.[25]  

25. So far, the record has been positive. The US side reports deeper understanding by both Japan and South Korea on the intricacies of deterrence and why and how they should contribute to strengthen it. With Japan, progress has been made in the context of the 2015 revision of the US–Japan Defence Cooperation Guidelines, which have modernized the alliance by calling for an integrated whole-of-government approach to alliance cooperation.[26]  With South Korea, consultations resulted in the 2013 US–South Korea Counter-Provocation Plan, which calls for an immediate, proportional response with similar weapons if North Korea carries out a provocation.[27]  Japan and South Korea have also ramped up investments in missile defence systems or conventional forces. Over the last decade, the United States and Japan have developed, deployed and operated missile defences, both separately and together, and over the past couple of years a debate has emerged in Japan about its possible development of conventional strike capabilities to complement US options.[28]  While South Korea took longer to acquire advanced missile defence capabilities, it has just agreed (despite strong Chinese objections/pressure) to deploy US Terminal High Altitude Area Defence batteries, known as THAAD.[29]  The United States has also supported an increase in the range of South Korea’s missiles to improve deterrence of North Korea.[30] 

26. Looking to the future, the challenge for the Extended Deterrence Dialogue and Deterrence Strategy Committee is twofold. For starters, they need to continue to provide appropriate assur-ance and deterrence responses to the changing regional security environment. Second, and relatedly, these dialogues, which have a strong operational focus, need sustained support at the political level. Plainly, they will need to pass the test of time. At present, enthusiasm is high to keep them going, so high that the United States and South Korea have just decided to create a second bilateral process, the Extended Deterrence Strategy and Consultation Group.[31]  Much remains unclear about the goals of this process and how it will differ from and interact with the Deterrence Strategy Committee, but the fact that it will be a higher, political level channel of communication suggests an interest in more, not less dialogue, at least between the United States and South Korea. Support for the Extended Deter-rence Dialogue has also been solid on both the US and Japanese sides, even though at present there is no indication that they will seek (and need) to establish an equivalent to the Extended Deterrence Strategy and Consultation Group.

27. Improved trilateral dialogue between the United States, Japan and South Korea on these issues is the logical next step to this framework of activity. This would be a welcome addition to the progress made in the two bilateral tracks given that the challenge of managing an escalating crisis in the region would likely involve all three allies. Trilateral cooperation, however, has proved difficult because Tokyo and Seoul have deep disagreements over historical (and territorial) issues and diverging threat perceptions – Japan is concerned about North Korea and China, while South Korea is almost exclusively preoccupied by North Korea. Significant progress has nonetheless been made in recent years, notably in intelligence sharing exchanges about North Korea.[32] Moreover, in its track-1.5 work, the Pacific Forum CSIS has highlighted important areas of potential dialogue and cooperation between the three allies, in particular to better deter, defend against and respond to attacks by North Korea.[33]  


28. The US rebalance to Asia (and Australia’s worries about the regional security environment, especially China’s re-rise) have led to important upgrades to the US–Australia alliance in recent years. Washington has vowed rotational deployment of US Marines through Darwin and Canberra has agreed to host US warplanes and fighter jets out of Darwin and Tindal and provide enhanced access for US Navy ships to ports around Australia.[34]  More generally, the United States and Australia have decided to increase the number and depth of military exercises and training.

29. No upgrades, however, have been made to the alliance’s strategic nuclear component. Unlike with Japan and South Korea, no SNPD has been established between the United States and Australia and no special tours of the US strategic nuclear arsenal have been organized for Australian officials. This aspect of the alliance has kept a low profile existence and remained an issue of interest only to a small number of policymakers and academics, mostly in Australia and in Canberra in particular.

30. Since the foundation of ANZUS, the strategic nuclear component of the alliance has been mostly an abstraction, remote from Australia’s (and New Zealand’s) immediate security concerns. During the Cold War, while US nuclear umbrella guarantees played a crucial role to avoid a divisive political debate on whether Australia should develop its own nuclear arsenal, Canberra was more concerned by the political upheavals in Indonesia than strategic nuclear dynamics.[35]  The 1976 Defence White Paper, for instance, noted that Australia has “an enduring interest in the security and integrity” of the Indonesian archipelago.[36]  Forty years later, Australians continue to have an interest “in a secure nearer region” but worry increasingly about a possible downturn in US–China relations and growing interstate competition, which the 2016 Defence White Paper ranks as the first and sec-ond drivers that will shape Australia’s security environment.[37]  Because Australia is less exposed than Japan and South Korea, however, its worries are much less acute, which explains why no decision has been made to upgrade the strategic nuclear component of the alliance.

31. Yet given the regional security environment’s current trend lines (that is, that China’s re-rise and military might will likely continue to grow and that the foreseeable future will get more, not less competitive), it would be useful for the United States and Australia to consider establishing a dialogue process similar to the Extended Deterrence Dialogue and Deterrence Strategy Committee. Because of Australia’s geopolitical position, however, this dialogue would have to be broader in scope: it would have to focus not only on deterrence and assurance, but also on other strategic issues, including, for instance, on ways to respond to China’s actions in South Chi-na Sea. If the domestic political sensitivity in Australia could be overcome, such a dialogue would be a welcome addition to the Australia–United States Ministerial (AUSMIN) consulta-tions. An annual process since 1985, AUSMIN is the principal forum for bilateral exchanges on defence issues between Australia and the United States, bringing together the Australian Foreign and Defence ministers and the US Secretaries of State and Defense, along with senior officials from both portfolios. Should a new dialogue be established, therefore, it would need to have a strong operational focus like the Extended Deterrence Dialogue and Deterrence Strategy Committee, leaving higher level matters to AUSMIN.

32. Looking to the future, some form of SNPD could also develop under the auspices of the increasingly mature Australia–Japan–US Trilateral Strategic Dialogue.[38]  While it would be counter-productive to use the Trilateral Strategic Dialogue as a tool directed against China, the three countries would benefit in comparing and contrasting their understandings of and approach to deterrence and assurance. Dialogue could also explore ways they would cooperate in a contingency. This would be a positive development at a time when Washington is promoting “spoke-to-spoke” linkages and could help provide a model of trilateral cooperation for US–Japan–South Korea efforts.


33. Strategic nuclear competition is on the rise. That competition is vastly different from that of the Cold War, which opposed two superpowers and could have led to global nuclear annihilation. Yet while this danger has now been relegated to the dustbin of history, today the presence of several nuclear-armed states, the complex interactions and interconnections between them and the emergence of new weapons of strategic significance as well as new domains of engagement (space and cyber) have increasingly made deterrence more challenging and arms races, escala-tion and even nuclear use more likely. 

34. Nowhere is this more evident than in the Asia–Pacific, where tensions have risen (and crises have broken out) not only between the United States (and its Asian allies) and North Korea and between them and China, but also be-tween India and Pakistan and increasingly between India and China. In these circumstances, SNPD between these various actors is paramount to increase mutual understandings and, hopefully, decrease the odds of war and, in particular, nuclear use. Yet while it has begun to develop, SNPD remains either vastly immature or active only at the track-2 or 1.5 levels, if at all. 

35. The first of two, this paper has explored the SNPD state of play between the United States and its Asian allies, where it is most developed. It has shown that much progress has been made in recent years, in particular to build SNPD between the United States and Japan and between the United States and South Korea. There is scope for enhancement, however, both in the two bilateral tracks and to promote trilateral US–Japan–South Korea cooperation. There is also an opportunity to launch SNPD between the United States and Australia and discuss these issues under the auspices of the Australia–Japan–US Trilateral Strategic Dialogue.

[1]Lawrence Freedman, “The Rationale for Medium-Sized Deterrent Forces” in Christopher Bertram (ed.), The Future of Strategic Deterrence (Hamden CT: Archon, 1981), p. 52.

[2]Strategic nuclear policy refers not only to deterrence (convincing an adversary that the costs/risks of an attack outweigh the benefits), but also extended deterrence (affecting the cost/risk calculations of adversaries targeting a US ally), assurance (convincing US allies of the US commitment to their defence), and reassurance (convincing adversaries that extended deterrence is defensive and does not threaten them if they refrain from aggression). As detailed later, while they are traditionally conducted with nuclear weapons, these strategies are increasingly pursued with non-nuclear capabilities as well. For more definitions, see Linton Brooks and Mira Rapp-Hooper, “Extended Deterrence, Assurance, and Reassurance in the Second Nuclear Age” in Ashley J. Tellis, Abraham M. Den-mark and Travis Tanner, Asia in the Second Nuclear Age (Washington DC: Strategic Asia 2013–14), pp. 268–70. 

[3]While track-2 dialogue involve academics who can interact more freely than high-ranking officials, track-1.5 dialogue includes both official and non-official participants.

[4]David Santoro, “A Asia–Pacific Strategic Nuclear Policy Dialogues 2: Asia’s Four Nuclear-Armed States,” APLN/CNND Policy Brief No. 27 (January 2017).

[5]The latest agreement is the 2010 New Strategic Arms Reduction Treaty, in place until it expires in 2021, or 2026 if it is extended for five years. 

[6]The United States removed its nuclear weapons from Taiwan and the Philippines in 1974 and 1976, respectively. With the 1991 “Presidential Nuclear Initiatives,” it withdrew its remaining nuclear weapons from the region, including from US ships and submarines. Before the island was returned to Japanese administration in the early 1970s, the United States also deployed nuclear weapons on Okinawa.

[7]Victor D. Cha, Powerplay: The Origins of the American Alliance System in Asia (Princeton NJ: Princeton University Press, 2016).

[8]SEATO, which included Australia, France, New Zealand, Pakistan, the Philippines, Thailand and the United Kingdom and the United States, was disbanded in 1977. Washington, however, still considers the Manila Pact – the mutual defence aspects of the treaty – active for Australia, France, New Zealand, Philippines, Thailand and the United Kingdom. See https://history.state.gov/milestones/1953-1960/seato 

[9]Brad Roberts, China–US Nuclear Relations: What Relationship Best Serves US Interests? (Washington, DC: IDA, 2001), p. ES-2.

[10]Brad Roberts, Nuclear Multipolarity and Stability (Washington, DC: IDA, 2000).

[11]While many have written about the “Second Nuclear Age” since the late 1990s, it is Yale University Professor Paul Bracken who has done the most to popularize the phrase, notably in The Second Nuclear Age: Strategy, Danger, and the New Power Politics (New York: St Martin’s Griffin, 2013). See also Ramesh Thakur, “Asia–Pacific and Global Nuclear Orders in the Second Nuclear Age,” APLN/CNND Policy Brief No. 21 (July 2016), http://www.a-pln.org/briefings/briefings_view/Policy_Brief_21_-_Asia-Pacific_and_Global_Nuclear_Orders_in_the_Second_Nuclear_Age 

[12]According to the International Law and Policy Institute, “In order to exist, a nuclear umbrella must both be con-tended and not explicitly refuted.” See http://nwp.ilpi.org/?p=1221 

[13]“Statement by the President on North Korea’s Nuclear Test,” Washington DC, 9 Sept. 2016. 

[14]Until its suspension from ANZUS in 1986, the same was true of New Zealand. Note that since 1997, New Zealand has been designated a “major non-NATO ally,” a status that does not automatically include a mutual defence treaty with the United States but confers military and financial advantages not available to non-NATO countries. See Title 10, section 2350a of the US Code, http://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title10-section2350a&num=0&edition=prelim 

[15]2016 Defence White Paper (Canberra: Department of Defence, 2016), p. 121.

[16]For more on the US–Thai alliance, including recent ef-forts to modernize it, see Catharin Dalpino, “Obama in Thailand: Charting a New Course for the Alliance?” Asia–Pacific Bulletin, no. 188, 4 Dec. 2012.

[17]See https://www.congress.gov/bill/96th-congress/house-bill/2479

[18]These are the terms of the 2014 Enhanced Defense Co-operation Agreement meant to bolster the US–Philippine alliance. See http://www.gov.ph/downloads/2014/04apr/20140428-EDCA.pdf 

[19]There is no appetite (in the United States or Asia) for “nuclear inclusion” of more US allies under the US umbrella, as some strategists have suggested. See Rod Lyon, A Shifting Asian Nuclear Order (Canberra: Australian Strategic Policy Institute, 2016), p. 26.

[20]The Extended Deterrence Dialogue and Deterrence Strategy Committee are products of the 2010 Nuclear Posture Review (NPR) drafting process. NPR drafters concluded that there was a need for institutionalizing dialogues with Japan and South Korea to alleviate rising security concerns and better explain and improve deterrence. See Nuclear Posture Review Report (Washington DC: Department of Defense, 2010), p. 32. For more on the rebalance, see Ash Carter, “The Rebalance and Asia–Pacific Security,” Foreign Affairs, Nov–Dec. 2016.

[21]In 2013, South Korean politician M J Chung argued South Korea should develop nuclear weapons. See speech transcript at http://carnegieendowment.org/2013/04/09/keynote-m.j.-chung-member-national-assembly-of-republic-of-korea-pub-51320 This proposal has received growing public support since the third North Korean nuclear test. See Jiyoon Kim, Karl Friedhoff and Chungku Kang, “The Fall-out: South Korean Public Opinion Following North Korea’s Third Nuclear Test,” Asan Institute for Policy Studies, Issue Brief, no. 46, 25 Feb. 2013, p. 7. Fresh calls have been made since. Meanwhile, while Japan developing nuclear weapons is more remote, it is not impossible. See Richard J. Samuels and James L. Schoff, “Japan’s Nuclear Hedge: Be-yond ‘Allergy’ and Breakout” in Asia in the Second Nuclear Age, pp. 232–64. For a more recent analysis, see Mark Fitzpatrick, Asia’s Latent Nuclear Powers: Japan, South Korea, and Taiwan (London: IISS Adelphi Book 455, 2016).

[22]The Pacific Forum CSIS conducted US–Japan and US–South Korea track-1.5 extended deterrence dialogues in 2008–13 and 2009–13, respectively. Reports are available at www.pacforum.org

[23]Nuclear Posture Review Report, p. 19.

[24]While the Extended Deterrence Dialogue and Deterrence Strategy Committee are equivalent in seniority and substance, the Extended Deterrence Dialogue is co-chaired by the US State and Defense departments and the Japanese Foreign Affairs and Defence ministries, whereas the Deterrence Strategy Committee is co-chaired by the US Defense Department and South Korean Defence Ministry with participation from the US State Department and the South Korean Foreign Affairs Ministry.

[25]Of late, there has been growing integration of nuclear and conventional capabilities in military planning, allowing for tighter cooperation between the United States and its allies. For more on nuclear-conventional integration, see Vincent A. Manzo and Aaron R. Miles, “The Logic of Integrating Conventional and Nuclear Planning,” Arms Control Today, Nov. 2016, pp. 8–14.

[26]The New Guidelines for Japan–US Defense Cooperation, 27 April 2015, http://www.mofa.go.jp/files/000078188.pdf 

[27]“Officials Sign Plan to Counter North Korean Threats,” DoD News, 24 March 2013. 

[28]See Brad Roberts, “Extended Deterrence and Strategic Stability in Northeast Asia,” NIDS Visiting Scholar Paper Series, no. 1, 9 Aug. 2013, pp. 18–24.

[29]See http://missiledefenceadvocacy.org/intl-cooperation/republic-of-korea/ 

[30]Daniel Pinkston, “The New South Korean Missile Guide-lines and Future Prospects for Regional Stability,” International Crisis Group, 25 Oct. 2012.

[31]“Joint Statement of the 2016 United States–Republic of Korea Foreign and Defense Ministers’ Meeting,” Washington, DC, 19 Oct. 2016.

[32]After failing to sign a “General Security of Military In-formation Agreement” in 2012 allowing them to share military intelligence on North Korea, Japan and South Korea agreed to do so a three-way pact with the United States in 2014. Two years later, in late 2016, they finally signed a General Security of Military Information Agreement, removing the United States as an intermediary. See “South Korea, Japan agree intelligence-sharing on North Korea threat,” Reuters, 23 Nov. 2016.

[33]Since 2013, the Pacific Forum CSIS has conducted US–Japan–South Korea track-1.5 extended deterrence dialogues. Since 2014, these dialogues have included table-top exercises featuring an escalating crisis on the Korean Peninsula. Meeting reports, including table-top exercise summaries, are available at www.pacforum.org

[34]See Peter Jennings, “The US Rebalance to Asia–Pacific: An Australian Perspective,” Asia Policy, Issue 15, Jan. 2013, pp. 38–44.

[35]See Christine M. Leah, Australia and the Bomb (New York: Palgrave Macmillan, 2014).

[36]Australia Defence (Canberra: Department of Defence, 1976), p. 7.

[37]2016 Defence White Paper, p. 40.

[38]Security cooperation has expanded considerably between the three countries since trilateral cooperation first began in 2002. See Yuki Tatsumi (ed.), US–Japan–Australia Security Cooperation (Washington DC: Stimson Center, 2015).

David Santoro is director and senior fellow for nuclear policy at the Pacific Forum, Center for Strategic and International Studies, where he specializes in strategic and deterrence issues as well as non-proliferation and nuclear security, with a regional focus on Asia–Pacific and Europe. Before joining the Pacific Forum CSIS, he worked on nuclear policy in France, Australia, Canada and the United Kingdom. He has also been a visiting fellow at New York University's Center on International Cooperation and a Stanton Nuclear Security Fellow at the Institute for International Strategic Studies in London. You can follow him on Twitter at @DavidSantoro1.