Bilahari Kausikan: The Korean Peninsula and the future of East Asian geopolitics

Since at least the late 19th century, what happens on the Korean Peninsula has affected all of East Asia, and indeed all of the Asia-Pacific. But too much thinking about the Korean Peninsula has been trapped for too long in a rut from which it is only tentatively emerging. At a time when global geopolitics is rapidly changing, this can be dangerous. Even if worst-case scenarios are avoided, this represents lost opportunities.

The fourth shift

Three times in the last four centuries since Toyotomi Hideyoshi unified Japan and then invaded Korea in 1592 in defiance of the Sinocentric regional order, the Korean Peninsula has played a pivotal role in the making and remaking of East Asian geopolitics and regional order. Events on and around the Korean Peninsula were central to the First Sino-Japanese War of 1894, the Russo-Japanese War of 1904, and, of course, the Korean War in 1950. 

China’s defeat by Japan revealed the vulnerability of the Qing Dynasty, marked the final dissolution of the Sinocentric regional order, and accelerated a scramble to carve the Qing Empire into spheres of influence; Russia’s defeat signified the initiation of Japan into the Western colonial order and started the sequence of events that led to Korea’s loss of sovereignty in 1910 and, ultimately, to the Second World War; the Korean War divided the peninsula and defined the American defence perimetre in East Asia as it exists to this day. 

As the second quarter of the 21st century begins, I believe that we are on the cusp of a fourth shift in East Asian geopolitics that, at least potentially, could permanently reshape the East Asian regional order. This fourth shift could thus be even more momentous than the three previous shifts. 

The Korean Peninsula will again be pivotal in this impending reordering of East Asian geopolitics. There is, however, a crucial difference between the fourth shift and the previous three. Although Korea has never been entirely without agency and at times exercised its agency decisively, in 1592, 1895, 1905 and 1950, it was nevertheless much more arena than actor. But now both the Republic of Korea (ROK) and the Democratic People’s Republic of Korea (DPRK) can be full and crucial actors. 

The fourth shift in regional geopolitics will be driven by two inter-related factors:

First, America’s global strategic posture is moving from direct involvement on the ground to off-shore balancing. This is not entirely new, as off-shore balancing has been the norm in East Asia since the end of the Vietnam War, with American ground forces in South Korea as the exception. What is new is that off-shore balancing will be the new American global norm and not just a regional norm. After its withdrawal from Afghanistan, the US has shifted to off-shore balancing in the Middle East — it is fighting Iran as an off-shore balancer — and it is a matter of time before it shifts to an off-shore balancing posture in Europe as well, the Trump administration’s change of attitude towards Ukraine being a portent of the future.

Second, North Korea’s nuclear weapons and missile development programmes and, in the broader context, China’s nuclear modernisation programme, which aims at matching the nuclear arsenals of the US and Russia and improving the survivability and hence credibility of its second-strike capability. 

No existential crisis

It would be a mistake to think of the shift to off-shore balancing as America retreating from the world. It is better understood as a unilateral redefinition of the terms of American engagement with the world based on a narrower and more transactional calculation of American interests. It would also be a mistake to attribute this shift solely to the particularities of the Trump administration or the president himself. US President Donald Trump certainly has a unique personality, but he and his administration are as much symptoms of, or a catalyst for, broader structural changes in the American body politic and the international system. 

After the collapse of the Soviet Union and the end of the Cold War, the US faces no existential threat anywhere in the world. China may be a peer competitor but is not an existential threat to the US. Efforts to frame US-China rivalry as a “new Cold War” evoke an intellectually lazy metaphor and focus on the superficial and not what is core to their competition. Russia is certainly an existential threat to Ukraine, but not to the US. North Korea may pose a serious threat to neighbouring Japan and South Korea but not to the US; likewise Iran, a very serious threat to its neighbours, but not the US. 

Without an existential threat, there is no compelling reason for the US to, paraphrasing President John F. Kennedy at the height of the Cold War, bear any burden, pay any price or fight any foe to uphold international order on behalf of its allies, partners and friends. To President Trump and those Americans who twice voted him into office, it was thus time to put “America First”.

Putting America first is not the same thing as the isolationism of the 1920s and 1930s. Changes to the fundamental structure of the global economic system are unlikely. Globalisation will slow and become patchy, but apocalyptic scenarios of its reversal or disintegration lack credibility. The US is still the largest market, the source of most technological innovation, and while other currencies are nibbling around its edges, there is still no credible substitute to the US dollar’s international role. That makes the isolationism of the past well-nigh impossible. But since the fundamental cause of the change of American attitudes is structural — the end of the US-Soviet Cold War — it is wishful thinking to assume that future administrations, regardless of party, will differ in anything but form. 

The relatively generous American policies and attitudes we had assumed as the norm were in fact an artefact of a particular set of historical circumstances that have passed and will not return. A new president may express himself more temperately, but in substance, the narrower and more transactional definition of interests that drives American foreign policy today is unlikely to change very much. The US will continue to demand more of its allies, partners and friends and will not support them unconditionally.

Disillusioned allies

Unilateralism, threats and coercion are not recent inventions of President Trump. They have never been absent from American diplomacy. Pre-Trump America was never some prelapsarian paradise. The City upon a Hill has always cast dark shadows. This is a harsh fact more evident to those who live below the Hill than on it. America’s western allies — in particular Canada and Europe — have been traumatised to find that in the eyes of post-Cold War America, their place was with the hoi polloi in the shadows and not, as they had convinced themselves, up in the sunlight on the Hill with the US.

This is not a delusion that any US ally in East Asia has seriously harboured. Half a century ago, East Asia received a shock, analogous to the shock administered to Western allies by the Trump administration’s change of attitude towards Ukraine, when the US, having decided that the war in Vietnam was not worth the effort, withdrew its forces, leaving those in South Vietnam, Laos and Cambodia who had naively trusted America, to their bitter fates. There was only minimal consultation with South Korea that had been fighting alongside America, and it is difficult to believe that those consultations had any significant effect on US policy. Earlier, Japan was notified only minutes before US President Richard Nixon’s 1972 visit to China; South Korea not at all. There have been other shocks as well. Not surprising therefore that America’s East Asian allies, partners and friends, have since dealt with the US much more on the basis of common interests than the illusion of common values. 

Throughout my career, I have been periodically asked if I thought the US was reliable. I have always given the same answer. Of course the US is not reliable, but it is indispensable and so the question of its reliability is moot. 

The foundation on which our region’s prosperity depends on is an equilibrium in which the US is an irreplaceable component. Regardless of who occupies the White House, we and other US allies, partners and friends in East Asia, will deal with the US pragmatically and do what we must to keep it engaged. Naturally, East Asian countries that share common interests will work more together, and with countries across conventional regional boundaries, to hedge against the vagaries of a more transactional post-Cold War America. They have begun to do so. But there is no possible combination of countries anywhere that can balance China or deter Russia without the US at least minimally in the equation. The stability provided balance and deterrence is the sine qua non of any combination of countries working effectively together. If you think otherwise, you are only deluding yourself.

The nuclear question

Despite the stresses that the Trump administration has undoubtedly placed on them, US alliance systems will therefore survive — there is no alternative — although they will not be exactly the same as before. The current stresses are real but only epiphenomenal. The second factor I mentioned earlier — China’s nuclear modernisation and North Korea’s nuclear weapon programmes — raise much more fundamental and consequential questions. 

In his book entitled Diplomacy published in 1994, the late Henry Kissinger defined the core issue when he analysed how nuclear weapons had changed intra-alliance relations. Kissinger argued that before the nuclear age, “the consequences of abandoning an ally were deemed to be more risky than fulfilling one’s obligations. In the nuclear age, this rule no longer necessarily held true; abandoning an ally risked eventual disaster, but resorting to war at the side of an ally guaranteed immediate catastrophe.” South Korea and Japan should think about Kissinger’s cold logic. 

North Korea is now a de facto Nuclear Weapon State even if not officially recognised by the Non-Proliferation Treaty (NPT) as one. President Trump has referred to North Korea as a “nuclear power”, to the fury of NPT purists. But he was only stating a simple fact that is not going to be reversed. North Korea is never going to give up its nuclear weapons. Pyongyang considers nuclear weapons as vital for regime survival and thus an existential issue. There is no cost we can impose on Pyongyang that is higher than the cost of abandoning an existential issue. Nor is there any incentive that we can offer that will bring benefits that are worth the risks of abandoning an existential issue. Now that it has nuclear weapons, however few or rudimentary, disarming North Korea by force is no longer an option.  

China will not help denuclearise North Korea in any meaningful way. Beijing dislikes North Korea’s nuclear weapons programme. But since Pyongyang considers nuclear weapons vital for regime survival, Beijing will never do anything that could jeopardise the survival of a fellow Leninist state — one of only five left globally — or which could be construed as being complicit in regime change. To do so risks giving the Chinese people inconvenient thoughts about their own regime and that is too great a risk. To China, accepting a nuclear North Korea is a lesser evil. 

There may be a growing alignment of views between the US and China on this issue. Beijing has avoided talking about denuclearisation of the Korean Peninsula for some time. When President Trump met Chinese President Xi Jinping in Beijing earlier this year in May, the White House said that the two leaders “confirmed their shared goal to denuclearize North Korea” but Beijing’s account of the talks did not mention denuclearisation. However, four months later during their September summit, neither side mentioned denuclearisation in their accounts of what was discussed on North Korea.

Diplomatic efforts with North Korea

This underscores what was clear for some time: denuclearisation of the Korean Peninsula — in whatever definition of that elusive phrase — is an impossible dream. We can now only deal with a nuclear-armed North Korea through diplomacy based on strong deterrence. If we acknowledge this hard fact, two questions arise: one, what is the future of American extended deterrence? Two, can a nuclear weapon state be deterred by conventional means?

During a press conference in February 2025, President Trump claimed that his North Korean diplomacy had stopped a war. This may or may not be true. But he has certainly dealt with North Korea far better than his predecessors. When he was president, Barack Obama made pretty speeches but came across as weak. His administration did nothing about North Korea for eight years and called it a policy of “strategic patience”. Neither did the Biden administration take any meaningful initiative on North Korea. Their inaction eroded deterrence and allowed Pyongyang to advance its missile and nuclear weapon programmes.

I am tempted to say that it takes a thug to deal with thugs but that would be impolite and unkind, and I like to think I am neither. So I will only point out that in August 2017, after North Korean leader Kim Jong-un threatened to hold missile tests with an impact zone near Guam, President Trump responded by threatening to rain “fire and fury” on Pyongyang. The test was delayed and later that month, North Korea instead tested a missile that over-flew Japan and landed in the North Pacific far from Guam. Since then, as far as I have been able to ascertain, North Korea has not tested long-range missiles on any trajectory that would bring it anywhere near Guam. 

Deterrence restored, President Trump met with Kim three times during his first administration: in Singapore in 2018, and in Hanoi and at the DMZ (Korean Demilitarised Zone) in 2019. These meetings failed because they were hastily prepared and set vague and unrealistic objectives. To expect “Complete, Verifiable and Irreversible Denuclearization” (CVID) of North Korea’s nuclear programme, a long-standing goal of US policy, is a fool’s errand. CVID is an obstacle to dealing with North Korea’s nuclear programme in a practical and realistic manner. The US should officially abandon it.

President Trump has expressed interest in meeting Kim Jong-un again. So far Pyongyang has rebuffed his overtures, but this is what they did to the first Trump administration before abruptly reversing position. In my meetings with North Korean officials, they have been consistently clear that the main threat to regime survival is the US and prioritise the US over South Korea and Japan. One senior North Korean official even went so far as to bluntly tell me why speak to the dogs rather than their master! North Korea’s distrust of China is perhaps as great as their distrust of the US, or at least North Korean officials have spoken of both to me in almost the same uncomplimentary terms. I once feigned ignorance and rhetorically asked another North Korean official why they distrusted China when it was a formal ally and had intervened to help the DPRK during the Korean War. He looked at me as if I was a moron and said America is far but China is near and that I should read more Korean history. 

What North Korea wants

What North Korea wants is a peace treaty with the US and formal recognition as a nuclear weapon state in order to ensure regime survival and broaden its manoeuvre space vis-à-vis China and Russia. Some will argue that a peace treaty will reward and thus encourage bad behaviour. This is unconvincing. Rewarding bad behaviour is hardly unknown in international relations. What else was the 1995 KEDO (Korean Peninsula Energy Development Organization) agreement but an attempt to bribe Pyongyang to stop behaving badly? KEDO failed. But North Korea then had no nuclear-weapons capability. Its development of such a capability, however rudimentary, could change its calculations of interests, particularly when it develops a minimally credible second-strike capability vis-à-vis the US, boosting its confidence in regime survival. 

Whether or not there should be a peace treaty is something that the US should decide in consultation with South Korea because in effect it will mean an end to reunification even as an aspiration, and de jure and not just de facto recognition of two Korean states. In January 2024, Kim Jong-un renounced peaceful reunification as a policy goal and demolished the Reunification Arch in Pyongyang, reportedly calling it an “eyesore”, which it was. Although this was accompanied by belligerent rhetoric and was certainly an act of immense symbolic significance, we should not assume that this indicates Kim Jong-un intends to fight a war of reunification. Its real symbolic significance lies elsewhere.

When I first visited Pyongyang in 2006, I was taken to Nampo Port because North Korea wanted our advice on how the port could be upgraded. I had some officials from the Port of Singapore Authority with me. They thought Nampo Port had potential but the main constraint to its development was Nampo Dam or the West Sea Barrage located about 15 kilometres down river from the port, which closes off the Taedong River from the Yellow Sea. There are locks in the dam but they only allow ships of up to 50,000 tonnes to pass. Nampo Port officials refused to even think about any modification, however slight, to the dam because they said it had been personally designed by Kim Il-sung. 

If North Korea refused to contemplate any modification to a purely utilitarian structure because of its connection to Kim Il Sung, that his grandson could destroy the far more emotionally charged Reunification Arch built to commemorate reunification proposals by Kim Il Sung signifies a healthy move out of the deep shadows of his father’s and grandfather’s legacies. This opens possibilities that we should not refuse to explore.

Credibility of nuclear umbrella

Polls, including one in October 2025 by the government-funded Korea Institute for National Reunification, show that significant numbers of  South Korean polled — for the first time, a majority — are not interested in reunification, either thinking it unnecessary or opposed to it. To reduce the risk of miscalculation, it is better that North and South Korea deal with each other as separate sovereignties and that the US, Japan and South Korea recognise North Korea and conclude a peace treaty with it. A Korean two-state solution and acceptance of regime survival in the north is a relatively modest price to pay for stability on the Korean Peninsula. This may lead to discussions on arms control and non-proliferation which I think are the only realistic goals for nuclear diplomacy with North Korea. In any case, what are the alternatives?  

Even if South Korea and the US are willing to accept a peace treaty, diplomacy will still be difficult because Kim Jong Un now feels stronger. Closer ties with Russia have given him more manoeuvre space, including with China. But we should not dismiss a second attempt at diplomacy with the more realistic goal of arms control. 

If the Trump administration again tries diplomacy, what type of arms will the US try to control? We do not know for sure. But in 2018, then Secretary of State Mike Pompeo said that the main objective of talks with North Korea was to eliminate Pyongyang’s long-range ballistic missile capability. I do not think North Korea will accept significant curbs on its long-range missiles because this means Pyongyang giving up the capability to deter the US. But other aspects of arms control and proliferation are worth exploring. Still, that the US has publicly said that its focus is on North Korean long-range missiles is something South Korea and Japan should ponder.

There are serious questions about American extended deterrence that diplomacy cannot resolve. During his first presidential campaign in 2016, Trump floated the possibility of allowing Japan and South Korea to acquire nuclear weapons as a cheaper way of defending them. We do not know how serious he was, but we should not rule out any possibility. 

Sixty-five years ago, during the Berlin crisis, French President Charles de Gaulle asked US President John F. Kennedy whether the US would be willing to trade New York for Paris if war with the Soviet Union broke out. Kennedy responded by observing that if France, an old American ally, could question American resolve, Soviet Union Premier Nikita Khrushchev could question it too. This was a clever diplomatic answer but one that begged rather than addressed the issue raised by de Gaulle. It was perhaps an adequate answer for those distant times. But US allies in East Asia should carefully examine the nuclear umbrella of the more transactional contemporary America in the light of North Korea’s nuclear weapons and China’s significant improvements to its second-strike capability. 

There are ways of prolonging the credibility of the nuclear umbrella. South Korea and Japan conduct regular talks with the US on extended deterrence. But the very fact that talks are necessary implies that credibility cannot be taken for granted and regular reassurance is needed. The most essential question will never go away. Will Los Angeles be sacrificed to save Seoul or Tokyo? This is a question only Koreans and Japanese can answer. But I know what my answer would be if I were Korean or Japanese. The related question is whether a nuclear weapon state can be deterred by conventional means. My own answer is that this is an extremely risky proposition. Some opinion surveys suggest that many South Koreans would agree.

A nuclear South Korea and Japan

I believe that the changes in the strategic environment that I have outlined have already set in motion a trajectory that now only makes it a question of when, not whether, South Korea and Japan will acquire independent nuclear deterrents. This will not be a replacement for their US alliances, but the means of preserving them. Otherwise, as the credibility of American extended deterrence erodes — as it inevitably will — the alliances will gradually loosen and eventually dissolve. To forestall such an eventuality, the US will acquiesce in both countries acquiring independent nuclear deterrents within its alliance framework. The US  has long acquiesced in latent Japanese nuclear ambitions, and here are recent signs that the US is moving in that direction with regard to South Korea as well.

I am not arguing that either South Korea or Japan are eager to acquire nuclear weapons. I do not underestimate the domestic political and diplomatic difficulties that acquiring independent nuclear deterrents will entail. China can be expected to put great pressure on Seoul and Tokyo and instigate other countries to do so as well. But the logic of their strategic circumstances will push both countries in that direction whether they want to or not and regardless of pressures. This is not a decision that needs to be taken immediately. But neither is it a decision that can be postponed indefinitely without grievous risk. 

The main risk faced by South Korea and Japan is not a cataclysmic war. Such a risk is an inherent characteristic of international relations and therefore never entirely absent, but in my view is not very probable. The more probable and more invidious risk is that as the credibility of American extended deterrence erodes, without independent nuclear deterrents, there will be a long and slow degradation of South Korean and Japanese autonomy by a series of almost imperceptible steps, each justified as a reasonable compromise to avoid confrontation with a nuclear-armed neighbour, the end result of which will be a South Korea and Japan that still exist as separate polities but are something less than fully sovereign. 

In this scenario, the neighbour of greatest concern is China. North Korea causes more immediate anxieties, particularly to South Korea, but viewed against the broad sweep of East Asian history, North Korea is a second-order issue. Will South Korea and Japan accept subordination to China? I think not. Korea and Japan — and in Southeast Asia, Vietnam — are the East Asian countries that have, over millennia, absorbed and integrated the most from Chinese culture into their own cultures yet remain distinctively themselves. To accept subordination to China will in effect negate much of their histories and require such a painful redefinition of what it means to be Korean and Japanese that any other option will be better. South Korea and Japan will act as each other’s spur. It is inconceivable that one will lag behind if the other decides to move ahead.

The NPT will not be a serious obstacle to either South Korea or Japan acquiring nuclear weapons once they decide to do so. One of the casualties of the Ukraine war is the NPT, which in any case, has never been anything but a frail bulwark against nuclear proliferation. No country that decides for whatever reason that it needs nuclear weapons will let the NPT or any other diplomatic document stand in its way. Ukrainian President Volodymyr Zelenskyy has publicly regretted that Ukraine accepted the 1994 Budapest Memorandum by which it gave up the nuclear weapons it inherited from the Soviet Union in return for paper security guarantees that proved worthless. Had it not done so, Ukraine would not be in an existential struggle for national survival. Other countries have taken note. Long before the first phase of the Ukraine war started in 2014, North Korean officials once asked me why I thought Kyiv had been so foolishly naive. I had no good answer.

The South Korea-Japan dynamic may revive Taiwan’s nuclear weapon ambitions. In the mid-1960s, Taipei pursued a secret nuclear weapons programme until a defector exposed it and the US forced it to shut down in the late 1970s. Unlike in the case of South Korea and Japan, even a more transactional US will not tolerate Taiwanese nuclear ambitions because it would almost inevitably mean war. If Taiwan shows any sign of seriously reviving a nuclear weapons programme, China cannot afford not to pre-empt it because a nuclear-armed Taiwan would end any prospect of reunification. The Chinese Communist Party’s legitimating narrative of achieving the China Dream under its leadership will be so seriously undermined as to jeopardise its rule. War would be so disastrous to the entire region that China and the US will probably find common ground in preventing Taiwan from moving in that direction. 

Gangster logic of nuclear weapon states

The end result of the processes underway will be a five-way East Asian balance of mutually assured destruction between the US, China, Russia, North Korea, South Korea and Japan. The road from where we now are to where I think we will eventually arrive will be highly fraught and contentious, even dangerous. But the risks are manageable and the end result will be stabilising. Nuclear weapons make unilateral changes to the status quo too risky. Nuclear weapons kept what one scholar, John Lewis Gaddis, has called the “long peace” between the US and the Soviet Union. There is no reason to believe their effect in East Asia will be any different. All the actors in East Asia are rational. Pyongyang’s actions strike many as based on the logic of gangsters, but it is still logic. Indeed, reduced to its essential elements, the uncomfortable fact is that the logic of nuclear deterrence is, for all nuclear weapon states, gangster logic.

The American international relations theorist, Robert Jervis, has pointed out that in the nuclear age, mutually assured destruction is not a policy but a reality. In the East Asian context, the five-way balance of mutually assured destruction will establish and anchor a new multipolar reality that will prevent the region being dominated by any single major power. This is a good outcome for the middle and small powers of the region because it offers them maximum opportunity to exercise agency.

Just before the September Trump-Xi summit, the DPRK’s foreign minister, Madam Choe Son Hui, declared that it was ”inevitable to reorganise and fix the geopolitical structure centred on the DPRK with nukes.” I met Madam Choe when she was aide to six-party talks negotiator Kim Kye-gwan and the official in the foreign ministry in charge of North America. She struck me as extremely intelligent and able. Although I doubt that Madam Choe’s view of the new East Asian structure is exactly the same as what I envisage emerging, we should still take what she said seriously.

Looking forward

There is one qualification to the evolution of the stable East Asian geopolitical structure I have outlined. Korea-Japan relations have always been central to developments on the Korean Peninsula. A necessary condition is that South Korea and Japan do not let their complicated and painful past dominate their relationship and focus instead on what they have in common for the future. Otherwise there will be too much scope for China, Russia or North Korea to try and play games of divide and rule. This could be destabilising.

There are recent signs of a ROK-Japan rapprochement but they are still tentative and fragile. I do not think there will ever be any more explicit an acknowledgement of remorse for Japan’s wartime record than the late Japanese Prime Minister Shinzo Abe’s statement on 14 August 2015 on the 70th anniversary of the end of the Second World War. I do not think most East Asian countries expect anything more. China aside, South Korea is the only country in East Asia that regularly looks backwards rather than forwards in its relations with Japan. 

I understand that South Korea’s past with Japan was uniquely and exceptionally bitter, not confined to the Second World War. But is it really in South Korea’s national interest to continue to look backwards when so many serious common challenges lie ahead? Only South Koreans can decide but their decision will affect all of East Asia.

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