The U.S. Should Get Out of the Way in East Asia’s Nuclear Debates

A February poll found that 71 percent of South Koreans wanted their country to have nuclear weapons. Another in May found 70.2 percent supported indigenous nuclearization, with 63.6 percent in support even if that violated the Non-Proliferation Treaty (NPT). The drivers, unsurprisingly, are North Korea’s weapons of mass destruction (WMD) and China’s growing belligerence. These factors impact the Japanese nuclearization debate too, though interest there is noticeably lower. The United States has long opposed South Korean/Japanese counter-nuclearization. But in the light of the Ukraine war, Washington should not hegemonically dictate the outcome of its allies’ WMD debates.

NATO anxiety over possible Russian WMDs in the Ukraine war illustrates potential limits on U.S. counter-escalation when facing a nuclearized opponent. Western pundits have been quite candid that Russian nuclear weapons were the reason for rejecting the no-fly zone sought by Kyiv. Chinese and, especially, North Korean WMDs might play a similar blocking or limiting role in East Asian contingencies.

Importantly, U.S. guarantees to South Korea and Japan are formalized as treaty, whereas NATO is not similarly committed to Ukraine. But during the Cold War, Britain and France were incredulous enough that the United States would sacrifice “New York for Paris” that they built their own nuclear weapons despite formal U.S. guarantees. That same logic is at work in East Asia today. The United States will not sacrifice “Los Angeles for Seoul.”

China, with its relatively restrained nuclear rhetoric, is less the issue here than North Korea, which regularly and flamboyantly invokes its nuclear weapons. Pyongyang is not going to reform, will march relentlessly toward more and better WMDs, and is building its doctrine around their use, including possible tactical deployments.

Alternatives to direct South Korean/Japanese nuclear deterrence of North Korean WMDs are soft. Extended nuclear deterrence is weakly credible if it means nuked U.S. cities to defend South Korea or Japan. Missile defense does not work well enough to provide a roof against as many weapons North Korea appears to be building. China will not take serious action to stop Pyongyang. A negotiated deal—the best solution and hence discussed at length below—might control Pyongyang’s programs somewhat via missile or warhead limits or inspector access. But North Korea seems unwilling to negotiate seriously, is an untrustworthy counterparty, is unlikely to cut enough to relieve the existential threat its WMDs now pose to South Korea and Japan, and would demand exorbitant counter-concessions as payment.

This poor option set is already forcing “thinking the unthinkable” discussions in the region. South Korean President Yoon Suk-yeol has suggested preemptive strikes on North Korean missile sites in a crisis, and former Japanese Prime Minister Shinzo Abe suggested the return of U.S. nuclear weapons to the region. The sheer precarity of South Korean and Japanese exposure to a nuclearized/missile Orwellian tyranny—which will be evident yet again this year if Pyongyang tests another nuclear weapon as predicted—will make it increasingly awkward for the United States to hegemonically insist that Seoul, and Tokyo even, may not investigate all security options.

Worse, U.S. resistance to allied nuclearization assumes a traditional American internationalism that is no longer assured. One of the United States’ two parties increasingly disdains alliances and admires authoritarianism. If former U.S. President Donald Trump—or a similar Trumpist—retakes the U.S. presidency in 2024, American opposition to East Asian allies’ nuclearization will decline dramatically—if only because the United States will no longer care what they do. As president, Trump was more interested in personal relationships with regional autocrats like Chinese President Xi Jinping or North Korean leader Kim Jong Un than with traditional U.S. partners. He notoriously “fell in love” with Kim and signaled a desire to “blow up” the US-ROK alliance if re-elected. He also hinted at breaking the 1951 U.S.-Japan security treaty. So, there is a reasonable chance that South Korea will nuclearize after 2024 regardless of what the Americans think. U.S. abandonment of South Korea would also push the Japanese nuclearization discussion to the right.

This would not be the first time the United States has tacitly accepted another country’s nuclearization. Ostensibly, the United States has supported the NPT for decades. In practice though, Washington tolerates at least five other states—Britain, France, Israel, India, and Pakistan—being unwilling to build down their stockpiles. Using the vague standard implied by these examples—friendship with the United States; reasonable state capacity; and at least theoretically, democratic rule—South Korea and Japan more than clear the bar for what is effectively a U.S. NPT exemption.

Judged by U.S. behavior toward NPT contravention, the NPT is better understood as a U.S. effort to prevent unfriendly or hostile states from nuclearizing rather than as a blanket, “Global Zero” commitment to fewer nuclear weapons in the world. The United States does not pressure friendly nuclear weapons states, including itself, to meet NPT requirements. It gave up sanctioning India and Pakistan’s violation after just three years. Applying this more honest standard of U.S. interests to arms control, the NPT is of questionable utility in East Asia.

China, Russia, and North Korea already possess nuclear weapons and show no signs of building down. So there is no regional nuclearization cascade for South Korea or Japan to provoke, because it has already happened. . And Taiwanese nuclearization is unlikely, as Taiwanese elites are quite aware that their nuclearization would provoke China.

Next, there is an under-discussed NPT downside: It provokes the alliance-debilitating, “New York for Paris” debates mentioned above. If U.S. allies do not nuclearize and must rely on U.S. nuclear weapons for nuclear deterrence, then they will inevitably question whether the United States will use those weapons in their defense if that might incur a retaliatory nuclear strike on the U.S. homeland. The answer to that question is almost certainly no, as then-French President Charles de Gaulle realized 61 years ago. The easiest way to reduce this bitter, alliance-undermining dissension is to let U.S. allies self-insure via indigenous nuclearization.

Finally, South Korean/Japanese nuclearization could serve shared regional interests by providing supplemental, local deterrence (as British and French nukes did during the Cold War) and by improving alliance burden-sharing. Further, the threat of South Korean/Japanese nuclearization might finally prompt Pyongyang and Beijing to take North Korean denuclearization negotiations seriously. Should South Korea and Japan respect the NPT and Global Zero plan while China, Russia, and North Korea do as they will, the effective outcome is unilateral disarmament. This is politically and strategically infeasible; we regrettably live in a world of persistent nuclear armament.

Global Zero advocates, such as political scientist Scott Sagan, worry about the transactional issues of WMD possession because they are uniquely dangerous weapons. Indeed, theft, loss, rogue scientists, and so on are legitimate fears. But they are no more resonant with South Korea or Japan than with any other nuclear weapons state. Indeed, as liberal democracies with robust state capacities and preexisting, well-managed nuclear energy programs, they will likely be quite responsible, as Britain and France have been.

No one seriously believes Seoul or Tokyo will launch an out-of-the-blue, nuclear-first strike on an opponent; set up something like the A.Q. Khan proliferation network; sell WMDs to terrorists or other rogues; put Homer Simpson in charge of nuclear safety; or be so sloppy as to require something like the Nunn-Lugar program. Even Pakistan and India have been better with their arsenals than the panic of the late 1990s suggested. Even dictatorships have been cautious about these issues. And as democracies with a history of foreign-policy restraint, democratic peace theory suggests they would be good stewards, certainly better than East Asia’s autocratic nuclear powers.

There is generalized anxiety about a regional arms race, which South Korean/Japanese nuclearization might exacerbate. Perhaps, but as noted above, there is no local cascade to be sparked because it has already occurred. China, Russia, and North Korea have all moved first. China and Russia have established nuclear arsenals and no intention of complying with the build-down imperative. Russia’s growing rhetorical invocation of its nuclear weapons is a disturbing evolution. North Korea repeatedly agreed, non-bindingly since 1992, to avoid nuclear weapons—only to exit the NPT and keep building. It now has intercontinental ballistic missiles and several dozen nuclear warheads.

Ostensibly, South Korea and Japan are not competing in this race—but only because they outsource their nuclear deterrence to the United States. Extended deterrence does not remove the U.S.-Japan-South Korea alliance on WMDs from the East Asian security discussion. It only means they are not located in-theater. That may have value in keeping China from building more WMDs (although it is already doing so) or Russia from playing the nuclear card in the region as it does in Europe. But it is not stopping North Korea. And that is the core issue—always and again.

North Korea will not sign a deal that reduces its arsenal enough to reduce the strategic threat that brought Yoon to float preemption earlier this year. Even if Pyongyang signed a deal—and did not cheat—it would never cut deeply enough to obviate the existential threat it now poses to Japan and South Korea. Nuclear weapons are an excellent deterrent for North Korea, and tactically, they help equalize the conventional military competition with the South and the United States, where Pyongyang lags behind. Complete, verifiable, irreversible denuclearization is fantasy.

The negotiations between Kim, Trump, and previous South Korean President Moon Jae-in strongly suggest this. From 2018 to 2020, North Korea had the best chance in its history to capture a balance-positive deal with South Korea and the United States. Revealingly, Kim passed it up, even though the constellation of forces was nearly ideal for Pyongyang in two, overlapping dovish presidencies in the North’s primary opponents.

With Trump, Pyongyang had the best U.S. president ever for its interests. Trump loathed South Korea. He knew little about Korean history, nuclear weapons, or ballistic missiles; according to former Trump National Security Advisor John Bolton, Trump did not even prepare for his summits with Kim. Trump did not care about the U.S. position in East Asia and disliked U.S. allies generally. He desperately wanted to sign a peace deal with Kim to win a Nobel Peace Prize and help his reelection bid while Moon came from a South Korean left that has often been eager to engage with Pyongyang.

It is hard to imagine better counterparties to whom Kim might have made some genuine concessions with to receive large counter-concessions. Instead, Kim’s one serious offer to Trump, at Hanoi in 2019, was very unbalanced. Kim offered to shutter one aging nuclear plant for full sanctions removal. Even Trump realized this was a bad deal, and talks collapsed.

Finally, a South Korean/Japanese nuclearization discussion indicates a seriousness about their own security, which is long overdue. Cheap-riding and strategy immaturity among U.S. allies are long-established problems. This is glaringly obvious in Europe now, where local U.S. allies, much more impacted by the Ukraine war, are nonetheless buck-passing leadership of the response to America. The United States should discourage this if it is to finally achieve a more restrained, less sprawling foreign policy, a less gargantuan defense budget, greater focus on China, fewer forever war interventions, and so on.

If allied democracies want nuclear weapons, if their foreign-policy elites and voters decide to take this step, then the United States should accept that this is their choice. As a liberal alliance leader, the United States should not tell its partners what to do nor what they may even debate. South Korean/Japanese interest in WMDs is defensive, in good faith, and follows decades of restraint; it is obviously not offensively intended. The United States should want its allies to take greater responsibility, develop deep national security doctrines, spend more, stop turning to America for foreign-policy direction, and so on. Indeed, Yoon recognizes that in the very title of his Foreign Affairs article for the 2022 South Korean presidential election: “South Korea Needs to Step Up.” Precisely.

Allied cheap-riding is bad for the United States at home too. Militarized hegemony is deeply toxic to U.S. domestic politics. The American national security state is too large and intrusive. American policing has become militarized, and the culture fetishes soldiers and military violence in a manner unique and disturbing for a republic. Greater allied burden-sharing has long been a goal of U.S. foreign policy, and it would be good for U.S. republican values at home if America did less abroad. There is no reason why greater allied strategic responsibility should not include WMDs if well-governed democratic allies so choose.

No one wants more nuclearization if avoidable. The decision is momentous, and I do not endorse it. Ideally, arms control with North Korea would alleviate some risk, as would missile defense, while extended deterrence and Chinese resistance could encourage North Korea to slow down.

But these options are all poor and getting worse. The United States will not fight a nuclear war solely for its allies, a point which American analysts should be honest with even if U.S. officials dance around it. Direct South Korean/Japanese deterrence is increasingly a better option than these alternatives, and the United States should at least allow its allies to debate the issue without strong-arming them.