Some American allies in the Indo-Pacific have a nuclear umbrella provided to them during the Cold War and continue to do so even in the changed security scenario of the post-Soviet world order. Japan and South Korea are the two allies that come under the declared extended deterrence policy of the United States.
Emerging Challenges to “Extended Deterrence”:
However, three significant recent developments have posed serious challenges to US extended nuclear deterrence; and the relevance of this policy has come under intense scrutiny in the nuclear debate in the United States as well as in some countries in the Indo-Pacific region. The first development is obviously the Russian invasion of Ukraine that has not only led to a geopolitical transformation spanning the entire globe but also brought the question of potential nuclear confrontation back on the table of strategic calculations and debate on the issue of nuclear security and stability. Russian strongman Vladimir Putin’s warning of nuclear exchange and escalation in the face of stinging Western sanctions and arming of Ukraine has no doubt impacted the US policy calculations and military moves. It has also restored the focus on nuclear weapons whose importance was sought to be consciously reduced by the US and Russia through nuclear arms control and promotion of nuclear non-proliferation.
Moreover, a perception has been built that had Ukraine not given up its nuclear arsenal and not chosen to join the NPT as non-nuclear weapons state, it could have perhaps prevented the Russian military invasion. Although some argue that Ukrainian nuclear weapons were Russian weapons and under control of Russia, analysts have argued that if that was the case there was no need for the Budapest Memorandum that encouraged Ukraine to give up nuclear weapons in exchange of guarantee of its sovereignty by the parties to the agreement. What is important on matters related to nuclear weapons, its use or it’s deterrence power is perception. There has been concern, for instance, about nuclear bombs falling into the hands of the terrorists. There was also discussion about “dirty bomb”. There are those who argue that smaller countries do think that if only Ukraine had nuclear weapons, the Russian invasion would not have occurred. There is also an understanding of how the US approaches differently while dealing with a de facto nuclear weapon power like North Korea and a country like Iran that has not developed any nuclear weapon but has the potential to do so.
The second strategic development that poses a critical challenge to the extended nuclear deterrence is, in fact, North Korean nuclear tests, development of an arsenal, though maybe small one, and its repeated missile tests, including its success in acquiring the ICBM capability. The United States provided nuclear umbrella to South Korea at a time when North Korea only had a potent conventional capability. The US had stationed tactical nuclear weapons in South Korea to deter any North Korean military adventure. But North Korea has quit the NPT, built up its WMD capability and apparently has acquired the capacity to hit American mainland with its ICBM. Will the extended nuclear deterrence work, especially since the US tactical nuclear weapons have also been removed from South Korea?
The third crucial change in strategic scenario is growing aggressiveness and assertiveness by the People’s Republic of China alongwith its unprecedented economic growth story. Its military modernization is also understandable which is generally commensurate with high growth economic trajectory. China prospered by propagating a theory of “peaceful rise of China” and myriad countries around the globe sought to benefit from China’s economic successes and built progressive cooperation with it in trade and investment. But this theory turned out to be short-lived as China began to aspire for a superpower status, tried hard to establish a hegemonic order particularly in the Indo-Pacific, launched a gargantuan Belt and Road Initiative, disrupted the rules-based order by adopting an opaque economic strategy to subjugate smaller countries into a debt trap and, more significantly, used its military muscle to claim sovereignty over about ninety per cent of South China Sea and made illegal and aggressive land encroachment of neighbouring countries, including India, Nepal and Bhutan.
The final nail on the head was China’s hugely disproportionate response to US House Speaker Nancy Pelosi’s visit to Taiwan that actually clarified Beijing’s real intention of annexing Taiwan by use of force. Violation of Taiwan’s airspace by Chinese fighters, live-drill naval exercises surrounding Taiwan that virtually blockaded Taiwan for the duration of exercises; and its belligerent rhetoric sent shock waves in the region. Analysts feared that China could take a leaf out of Russia’s nuclear sabre rattling and invade Taiwan. China has also strategic differences with Japan and South Korea that are under US nuclear umbrella and thus the Taiwan crisis amidst the Ukraine War sparked an active debate on extended nuclear deterrence.
The US has so far successfully implemented its extended deterrence policy both by deterring perceived adversaries and by preventing its allies under its umbrella from going nuclear. The nuclear posture, declaratory policy, and diplomacy were the major tools to keep the extended nuclear deterrence in place and make it effective.
The US analysts are, however, increasingly concerned about the effectiveness of the nuclear deterrence because of mainly three factors: a. China’s nuclear modernization; b. expansion of North Korea’s nuclear and missile arsenals; and c. growing mistrust in allied countries about the effectiveness of the extended nuclear deterrence doctrine.
China has developed anti-access and area-denial capabilities, has enough fissile materials to make about a thousand nuclear weapons by 2030 and about 2200 intermediate range missiles, more than that of the United States. Although the Stockholm-based SIPRI estimates that there are 350 Chinese nuclear weapons, the Pentagon frequently makes an estimate of nuclear weapons that China can have, if it continues to expand and modernize its nuclear weapons. According to a US Defence Department Report released in 2021, China could have 700 deliverable nuclear warheads by 2027 and about 1000 by 2030. China has also vehemently refused to join the United States and Russia in nuclear arms control negotiations. According to American analysts, Chinese nuclear and missile expansion has altered the strategic balance in the Indo-Pacific posing serious challenge to current status of US extended nuclear deterrence capability. While the current nuclear posture seems inadequate in the face of Chinese nuclear and missile modernization, both risk and cost of extended nuclear deterrence are considered much higher than before. The Biden Administration at the same time is aware of the consequences of his predecessor Donald Administration’s attempt to undermine alliances to the extent of asking Japan and South Korea to develop their own deterrence capability to face nuclear challenges. It is emphasized now by responsible experts that more dialogue with allies are necessary to maintain their trust in American nuclear guarantee against existential threats. In addition, Biden Administration’s cancellation of ICBM and SLCM tests amidst the Ukraine War and Chinese live-wire military drill around Taiwan appear to have weakened the confidence of the allies in American security and “extended deterrence” commitments.
Japan’s anxiety over extend nuclear deterrence has increased in the wake of the Ukraine War. Tokyo extended wholehearted support to the Biden Administration’s strong stand and harsh sanctions against Russia. When President Vladimir Putin spoke of nuclear weapons in response, the security discussion and debate in Japan began to focus more on nuclear issues, especially the credibility of the US nuclear umbrella in the worst-case strategic scenario. Russo-Japanese strategic differences, unresolved and long pending territorial disputes and now the Japanese sanctions against Russia were worse enough when China’s brawny military methods to assert its position on Taiwan caused additional fret in Tokyo.
Japan has always portrayed itself as the only victim of nuclear attack and has championed nuclear disarmament to the hilt. Nonetheless, Japan’s opposition to nuclear weapons proliferation had a contradiction in the sense that it was under US nuclear umbrella. Although Japan and the US were alliance partners and the US maintained military bases and stationed large number of troops in those bases, both the countries still felt the need of a nuclear deterrence shield. As Sino-Japanese and Russo-Japanese engagement improved in the post-Cold War era, Japan felt somewhat secured and nuclear threats tended to cease to be part of normal Japanese security discourse. But the emerging tension in Sino-Japanese ties in the wake of Chinese naval activities around Shenkaku Island amidst Sino-US economic cold war, rising strategic cooperation between Moscow and Beijing and Tokyo’s robust sanctions against Russia and tough stand against Ukraine War have led to return of the nuclear deterrence issue to the top of the agenda of Japanese security debate. Following are some of the prominent developments worth scrutinizing:
South Korea’s Fears:
South Korean fears of reduced dependability of “extended deterrence” appear to be more candid and relevant in view of its acute hostile relationship with North Korea. All efforts by South Korea, its principal strategic ally, the United States, along with other interested parties, such as Japan to denuclearize North Korea and maintain Korean Peninsula as nuclear free zone have failed. On the contrary, North Korea after leaving the NPT and conducting nuclear test explosion has kept on bolstering its nuclear weapons capability. On top of that, it has consistently test-fired missiles—according to one count about 30 in 2022 itself. Of particular American concern to the United States that has postulated extended nuclear deterrence to South Korea is North Korean development of SLBM and acquisition of ICBM capability that can threaten continental United States. In addition, North Korea’s belligerence, stiff and aggressive rhetoric and periodic missile launches make it harder for South Korea not to worry about a possible nuclear attack. Seoul perceives North Korean nuclear tests and missile launches as provocative and wonders why Pyongyang spends so much on WMD programmes even amidst a pandemic. South Korean Foreign Minister recently said: “At a time when North Korean people are suffering the pain of a COVID19 spread, North Korea is using its crucial resources to develop nuclear weapons and missile….”
It is essential to note that the United States was not able to win the three-years long Korean War in the early 1950s. The United States was the sole superpower at that time. Neither North Korea nor its close friend China had nuclear weapons capability. Yet the United States that militarily intervened to fight back North Korean aggression across 38th Parallel Line under the UN Flag failed to decisively win the war. Theoretically, North and South Korea are still at war in absence of a peace treaty! In the late 1950s, the United States provided extended nuclear deterrence to South Korea. Tactical nuclear weapons were stationed in American bases in that country to deter any North Korean aggression. But all those weapons were withdrawn in 1991 in the backdrop of winding down of Cold War and a growing perception that North Korea would not commit aggression.
There were also off and on discussion over closing down the US bases in South Korea and withdrawal of US troops causing substantial ambiguity in the bilateral alliance. The defence dialogue between the United States and South Korea furthermore involved how to share decision-making authority over operation of bases, regulation of military personnel and launching war operations. The much bigger issue now, however, is the reliability and efficacy of extended deterrence against a North Korea that has proven WMD capability. South Korea and the United States are party to a Mutual Defence Treaty and it is significant to note that the extended nuclear deterrence is not stipulated in the treaty. Extended deterrence is predominantly based on American declarations and discussions during bilateral interactions. The most recent Korea-US integrated defence dialogue took place in August 2022 and the US repeated a usual declaration about its “ironclad commitment” to the defence of South Korea “leveraging the full range of U.S. military capabilities—to include nuclear, conventional and missile defense.”
The US extended nuclear deterrence has two goals: protect South Korea against an external nuclear threat and secondly to dissuade South Korea from developing nuclear weapons. It is also widely believed that despite presence of US military bases, personnel and nuclear umbrella, South Korea was secretly undertaking a programme to develop nuclear weapons in the early 1970s and gave it up under US pressure and persuasion. Emergence of North Korea as a nuclear weapon power and its belligerent behaviour, however, appears to have unnerved Seoul to some extent. The Trumpean approach to alliance relationship may be an aberration but it was a cautionary experience for South Korea. China’s intimate ties with North Korea and its periodic backing to Pyongyang in the face of international sanctions have also caused unease in South Korea.
Like the Japanese Government, South Korean Government also openly commits to remaining non-nuclear, and again like Tokyo, Seoul also seems to be in search for more vigorous indigenous capability to deter foreign aggression. Now the present Yoon Suk-yeol Government has asked the Biden Administration to redeploy tactical nuclear weapons in South Korea. The conservative newspaper Chosun IIbo has called for US-South Korea dialogue on making “practical preparations” to meet challenge of North Korean nuclear threat. A vast majority of South Koreans earlier this year voted for their country developing nuclear capability in an opinion survey!
The United States has been consistently making open commitments to both Japan and South Korea to defend them against nuclear threats or attacks. But the altered geopolitical landscape, return of nuclear weapons in strategic calculations of Russia, China and North Korea; helplessness of Ukraine, vulnerability of Taiwan to Chinese muscle flexing, North Korea’s nuclear sabre rattling, the damage done to faith in alliances by the Trump Administration, over cautious responses of the Biden Administration to Russia’s nuclear threat, Chinese bellicose moves in the Indo-Pacific and nuclearization of the Korean Peninsula have raised doubts over relevance, reliability and practicality of “extended nuclear deterrence.”
The Biden Administration first postponed and later cancelled its planned missile tests amidst President Putin’s repeated nuclear threats and China’s undeclared blockade of Taiwan during live-fire exercises in angry reaction to US House Speaker Nancy Pelosi’s visit to Taiwan. It may prove to be a responsible decision by the Biden Administration to refrain from accelerating US-Russia and US-China tension. But the questions that have been raised are whether “extended deterrence” is reliable when nuclear powers like Russia, China and North Korea could take provocative steps, as for instance, Russian invasion of Ukraine or Chinese confrontational activities in South China Sea and the Indian Ocean region. How effective would “extended deterrence” be when nuclear weapon powers threaten US allies with measures that are not existential threats but are serious and substantial? What are the alternative or complementary strategies available to US allies facing heightened tensions in their region?
The current nuclear posture of the United States seems to be inadequate to deal with the altered balance of power in the Indo-Pacific. Washington’s policymakers do recognize this and are aware of the additional risks and costs involved in maintaining an effective “extended deterrence.” There are also suggestions that allowing allies to develop their own deterrence capability would suit US interests and reduce both costs and risks . President Donald Trump out of the blue made this proposal, though in somewhat disturbing fashion. An article in National Interest journal has argued: “While it comes with risks, allowing U.S. allies to go nuclear might actually ease the security burden of the United States.”
The US Government is unlikely to accept such an idea. Nor are the Japanese and South Korean governments going to start nuclear weapons development programmes in the foreseeable future. Moreover, the United States has been holding periodic EDD or Extended Deterrence Dialogues with Japan and Integrated Defence Dialogue or IDD with South Korea to assure them that the US commitments are rock solid. But both South Korea and Japan are in the process of revising their defence policies, seeking more transparency and participation in US nuclear decision making rather than remain just recipients of “extended deterrence”.
The Biden Administration has to do lots of heavy lifting to explain and convince its allies about the significance and credibility of its “extended deterrence” policy. It has prepared the 2022 Nuclear Posture Review and submitted a copy of it to the US Congress, but there is delay in releasing the unclassified version. The Pentagon has given hints that there will be “continuity and stability” in U.S. nuclear policy by releasing a Fact Sheet. But there are many difficulties that still remain unanswered. While the US allies and adversaries appear to be anxiously waiting to see the contents of the unclassified NPR, there are concerns of serious nature within the US strategic community. Some of the issues raised by Franklin C. Miller, who has served as senior nuclear policy and arms control officer in the Pentagon and the National Security Council, are pertinent and thought provoking. His questions are based on the recently released Fact Sheet. First, the administration has expressed its “commitment to reduce the role of nuclear weapons”, but how does “it do so in a world in which Russia, China and even North Korea continue to field new nuclear capabilities…?” Secondly, he says according to the Fact Sheet the United States will “seek to avoid costly arms race”, but “what does this mean when it is widely acknowledged that Russia and China have been racing each other and racing ahead by fielding hundreds of new nuclear and nuclear-capable systems…?And there are such other questions that arise from the declaratory policy of the US Government.
Difficult days are ahead. Uncertainties are paramount. Climate change impacts and energy shortages have led to some kind of a return to nuclear energy policies by countries that recently sought to close down their nuclear reactors. New countries are showing interests in adopting nuclear energy in the energy-mix by building nuclear reactors, of course with external help. In the long run, none can deny the possibility of new nuclear weapon powers mushrooming because of lack of faith in the reliability of extended deterrence, expansion of nuclear reactors, and the fast changing balance of power and emerging geopolitical disorders.
 The author is Hon. Chairperson, Kalinga Institute of Indo-Pacific Studies and Formerly Professor and Pro-Vice Chancellor of Jawaharlal Nehru University
 Samuel H Hicky and Monica Montgomery, “Nuclear Issues in Ukraine Crisis,” Centre for Arms Control and Non-Proliferation, www.armscontrolcenter.org. The authors point out that Ukraine could not have used the weapons it had, as those were under Russian control.
 New York Times, 3 November 2021.
 Japan Times, 29August 2022.
 Interview with Prof. Taniguchi Tomohiko during his visit to Delhi, 1 September 2022.
 Global Times, 30 August 2022.
 Japan Times, 19 July 2022.
 Josh Smith, Explainer: Why U.S. nuclear deterrence tops S.Korea’s agenda for Biden summit, https://www.reuters.com/world/asia-pacific/why-us-nuclear-deterrence-tops-skoreas-agenda-biden-summit-2022-05-19/
 Ramakrishna Pathanaboina and Sanjeet Kashyap, “After Ukraine, Should East Asia Go Nuclear?, National Interest, 30 June 2022.
 Franklin C. Miller, The Mystery of the Missing Nuclear Posture Review,” The Dispatch, 25 August 2022.