In 1994, Ukraine gave up its nuclear weapons, in exchange for security guarantees from the United States and Russia to respect Ukraine’s borders and sovereignty.
In 2022, Russia violated that agreement, launching an unprovoked invasion of Ukraine’s borders, claiming pieces of its territory. In 2025, US President Donald Trump held talks with Russian leaders, falsely blamed Ukraine for starting the war, and reportedly offered a “peace deal” that would endorse Russian conquests of Ukrainian territory.
Contrast this with the experience of North Korea. In 2006, the country tested its first nuclear weapon and is now reckoned to have about 50. Despite being impoverished and surrounded by hostile powers and questionable allies, North Korea has never been seriously threatened with war in the years since it went nuclear. Indeed, during his first term, Trump went out of his way to accommodate and befriend North Korea’s leader.
The moral of these stories and others1 is painfully, uncomfortably clear. The modern world is a place where nuclear-armed great powers, led by authoritarian leaders, often feel the impulse to bully smaller nations.
If those smaller nations lack nuclear weapons, they lie prostrate and vulnerable at the feet of the bullies. But if they have nukes, they are much harder to push around. This doesn’t mean they’re impervious to attack — Israel has been struck by Iran and its proxies — but having nukes dramatically improves a small country’s security.
There are at least three smallish nations for whom this lesson is especially urgent right now. In Europe, Poland is menaced by Russia, which seeks to dominate Poland as it did under the Tsarist Empire and again under the USSR.
Trump is frantically appeasing and trying to befriend Russia, and the West European nations are not yet willing to fill the gap. If Ukraine falls, Poland will be next on Russia’s menu — and Russia will have plenty of newly conscripted Ukrainian troops to throw as cannon fodder against Poland.
In Asia, meanwhile, Japan and South Korea confront a bully far more powerful than Russia. China is the world’s manufacturing superpower, with industrial capacity far exceeding the US and all its Asian allies combined; even if Trump’s America decides it wants to defend Asia against a Chinese takeover, it’s not clear it has the ability to do so.
And as Palmer Luckey eloquently pointed out in a recent interview, there’s every indication that China wouldn’t be satisfied with the conquest of Taiwan — it’s building a case to claim Japan’s island of Okinawa, and might support a North Korean takeover of South Korea in order to turn the whole peninsula into a Chinese satellite state.
Poland, Japan, and South Korea need something to replace the failing deterrence of their alliances with the U.S. Almost exactly one year ago, I made the case that that “something” is nuclear weapons of their own. I usually wait at least two years to “rerun” a post of mine, but in this case the situation seems rather urgent and the message is painfully timely.
I don’t like nuclear proliferation any more than you do, but in the new terrifying world of authoritarianism and great power conquests, it’s probably inevitable; best to do it in a way that preserves as much as possible of the stability and freedom that Europe and Asia have rightfully come to treasure.
Anyway, here’s my post from last year:
I am, to put it mildly, very unhappy about the need to write this post. I’ve been putting it off for a long time. And yet I’m going to write it, because it’s true, and someone needs to say it, and warning people about unpleasant geopolitical realities has kind of become one of my roles as a blogger over the past year.
I wrote about how the US isn’t psychologically or economically prepared for war with China, about the US’ withered defense-industrial base, and about the vulnerability of world commerce to area-denial strategies. But today it’s time for me to write about the scariest of these topics — the need for controlled nuclear proliferation. Japan and South Korea, and possibly also Poland, need to create their own nuclear deterrents.
For my entire life, it’s been an article of faith among most of the people I know that nuclear proliferation is a bad thing. And that makes sense because nuclear weapons are truly terrifying weapons. The US and USSR had many close calls during the first Cold War; if even one of those had resulted in a nuclear exchange, much of human civilization would have been laid waste.
The more pairs of countries are staring each other down with nukes, the greater the chance that one of those pairs will have a false alarm or accidental launch. That simple math should make us terrified of nuclear proliferation.
Furthermore, from 1990 through 2010, nuclear disarmament made the world a lot safer. U.S. and Soviet/Russian nuclear stockpiles dwindled from over 60,000 between them to fewer than 10,000:
And fewer than 4,000 of those are actually deployed; most are kept in reserves or have already been retired.
So why on Earth would we turn our back on a successful strategy of disarmament and actually recommend that more countries build their own nukes? Isn’t that pure stark raving world-destroying insanity?
Well, no, for several reasons. First, I’m not recommending that countries go back to keeping tens of thousands of nukes on hair-trigger alert like the US and USSR did; instead I’m recommending that a couple of countries develop modest nuclear deterrents along the lines of France’s, the UK’s, or India’s.
Second, countries outside of the U.S. alliance system have been engaging in nuclear proliferation for half a century now, so to simply do nothing in the face of that strategy will not stop nuclear proliferation from occurring; it will simply make it one-sided.
Third, Russia’s invasion of Ukraine and China’s threat to invade Taiwan signals a new expansionism on the part of the totalitarian great powers, which will be difficult to deter conventionally. Fourth, internal political divisions mean that Japan, South Korea, and Poland can’t rely on the US nuclear umbrella like they used to.
Fifth, evidence from South Asia suggests that modest nuclear deterrents can act as a stabilizing force at the regional as well as the global level. And finally, breaking the one-sided taboo on nuclear proliferation will probably make it easier to set up an effective new global nonproliferation regime.
In other words, Japan and South Korea getting nukes is not a good thing, but it’s probably the least bad option available at this unhappy juncture.
Nuclear proliferation is already happening
The original five nuclear powers, as defined in the nonproliferation regime set up in the 1960s, were the US, the USSR, China, the UK, and France. These were also the countries with permanent seats on the UN Security Council, and they were the victors of World War 2. So the original list of approved nuclear powers made sense as an extension of the postwar global order.
Those states generally tried to keep nuclear weapons to themselves, but not always. It’s an open secret that China helped Pakistan build nuclear weapons:
In 1982, a Pakistani military C-130 left the western Chinese city of Urumqi with a highly unusual cargo: enough weapons-grade uranium for two atomic bombs, according to accounts written by the father of Pakistan’s nuclear weapons program, Abdul Qadeer Khan, and provided to The Washington Post.
The uranium transfer in five stainless-steel boxes was part of a broad-ranging, secret nuclear deal approved years earlier by Mao Zedong and Prime Minister Zulfiqar Ali Bhutto that culminated in an exceptional, deliberate act of proliferation by a nuclear power, according to the accounts by Khan…
According to Khan, the uranium cargo came with a blueprint for a simple weapon that China had already tested, supplying a virtual do-it-yourself kit that significantly speeded Pakistan’s bomb effort. The transfer also started a chain of proliferation: U.S. officials worry that Khan later shared related Chinese design information with Iran; in 2003, Libya confirmed obtaining it from Khan’s clandestine network.
France, meanwhile, helped Israel build a nuclear reactor to produce material for nuclear bombs.
Pakistan, once it had nukes, had few reservations about proliferating them. It helped Iran, which doesn’t quite have nukes yet, but is close. And it did succeed in helping North Korea to go nuclear.
Meanwhile, although China isn’t exactly happy that North Korea has nukes, it has steadfastly refused American entreaties to take strong action to force North Korea to denuclearize.
Chinese aid kept the North Korean economy and military afloat in the face of US sanctions, allowing it to build up its nuclear arsenal and its missile capabilities. And China has never showed much interest in helping to curb Iran’s nuclear program, buying a large amount of Iranian oil and enabling the Iranian economy to stay afloat in the face of US sanctions.
So nuclear proliferation is happening, and it’s mostly being done by China and its allies. Increasingly, this means that U.S. allies are facing nuclear-capable enemies without nukes of their own. India has nukes to balance Pakistan’s, and Israel has nukes to balance any future Iranian arsenal. But three key US allies are in a very perilous situation right now: Japan, South Korea, and Poland.
The US nuclear umbrella is no longer reliable
Japan, South Korea, and Poland have been staring down the teeth of nuclear-armed China, North Korea, and Russia for decades now.
But in the past, they could always rely on the US nuclear umbrella to protect them from those enemies. The US nuclear umbrella is an explicit or tacit agreement with an ally. The US promises that if someone nukes that ally, the US will use its own nuclear weapons in retaliation. In exchange, the ally agrees not to develop nuclear weapons of its own.
In the 1990s or the 2000s, the US side of that bargain was a credible promise. But under Donald Trump, the solidity of the nuclear umbrella was called into question. During his presidency, Trump demanded that South Korea and Japan pay the US to provide them with nuclear protection, implying that the nuclear umbrella was conditional.
Trump has consistently shown hostility toward NATO, threatening to withdraw from the alliance, and recently declaring that if he won the presidency again, he would encourage Russia to conquer any US allies that didn’t spend enough on their militaries.
Meanwhile, US politics has now developed a “MAGA” faction — loyal to Trump, but not dependent on Trump — that is openly friendly to Russia and hostile to NATO. House Speaker Mike Johnson has blocked aid to Ukraine, resulting in the momentum of the war shifting to Russia. A pro-Russia online media ecosystem, including Tucker Carlson and others, has gained influence on the Right.
In this situation, allies should not be confident that America would come to their defense with nuclear weapons if they were attacked. If a Democrat is President, the nuclear umbrella is probably still in place (barring Congressional stonewalling), but a Democrat will not always be President.
If Trump is rejected in 2024, a Republican will still probably win in 2028 or 2032, and that Republican will have to at least placate the “MAGA” wing that wants to support Russia and withdraw from NATO.
In other words, the US’s domestic political divisions mean that it’s no longer a reliable nuclear protector. It might still come to the aid of Japan or South Korea or Poland with nukes, but betting the continued existence of your country on what America might do is an incredibly risky strategy.
Attack of the Slow Empires
America’s descent into unreliability comes at the most perilous possible time for Japan, South Korea, and Poland. China and Russia are on the march, led by personalistic totalitarian dictators and emboldened by both US weakness and by China’s manufacturing dominance.
Russia has, of course, invaded Ukraine. But there’s no indication that swallowing it would satisfy Putin’s appetite. Estonia and Moldova are probably next on the menu, since the former has a large population and the latter has a Russian-controlled enclave. (Estonia is in NATO, but if Trump refuses to come to its aid when it’s attacked, NATO is a defunct alliance.)
But Russia’s real prize is Poland, which Russia views as its ancient and most dangerous rival for influence in the Slavic world. Russian government mouthpieces regularly issue threats against Poland:
In general, it’s clear that Putin wants to restore some sort of Russian control over all of the lands that were part of the old Russian Empire. Whether he has the capability to do that is another question.
Technology has shifted toward the defense, and drones, mines, and portable missiles are now fairly easily able to stop fleets armored vehicles in their tracks. Putin’s initial attempt to take Ukraine by blitzkrieg failed for this reason, and an attack on Poland wouldn’t go any better.
But Putin may not need a lightning victory in order to keep on rolling. He’s reoriented Russia’s entire economy around the Ukraine war and mobilized all of its manpower. With robust oil revenues, Chinese manufacturing support, and a demographic advantage over the other East European states, there’s no reason Putin can’t just keep on attacking and attacking for decades.
Renard Foucart believes that Russia is so committed to the Ukraine war that its economy basically now depends on continuing that war:
Russia’s economy has not collapsed. But it does look very different, and is now entirely focused on a long war in Ukraine – which is actually driving economic growth…Put simply, the war against Ukraine is now the main driver of Russia’s economic growth…
A protracted stalemate might be the only solution for Russia to avoid total economic collapse. Having transformed the little industry it had to focus on the war effort, and with a labour shortage problem worsened by hundreds of thousands of war casualties and a massive brain drain, the country would struggle to find a new direction…The Russian regime has no incentive to end the war and deal with that kind of economic reality.
Russia thus seems to be trying to invent a new kind of empire — a “slow empire”, for which perpetual war is a way of life instead of a means to an end. It may never execute the kind of rapid, lightning conquests that empires of the past hoped to achieve, but it will relentlessly grind forward for decades on end.
China hasn’t launched any major attacks yet, but it does seem to be moving in a bit of a Russia-like direction. In addition to its threat to conquer — excuse me, “reunify with” — Taiwan, China has been trying to slowly slice off bits of territory from India, the Philippines, and Bhutan. And it’s also now pushing a claim to the Japanese island of Okinawa — not some small outlying island, but an important Japanese province.
Thus, while Xi Jinping might not be quite as reckless or aggressive as Putin, he clearly seems to want to carry out a similar policy of continuous slow expansion. And China’s economic and population advantages over its neighbors are far larger than Russia’s; China can continue a “slow empire” strategy for many decades.
If you’re in the path of a “slow empire”, how do you defend against it? You can’t out-manufacture China or a China-supplied Russia. You can’t throw more bodies into the fray than China and Russia can. What do you do? Other than surrender, you basically have two choices:
- Get the US, West Europe, or other external powers to protect you, or
- Develop nuclear weapons.
For Japan and South Korea, the choice here is very clear. The US is their only external protector against China, and the rise of MAGA politics (and the shriveling of the US defense-industrial base) means that the US is no longer reliable.
Nuclear weapons are the only real possibility of an enduring security guarantee for Japan and South Korea. And that’s not even taking into account the need to deter the loose cannon of North Korea, whose nuclear-capable missile arsenal is growing more deadly by the day.
For Poland, the case is less clear. It has another potential protector besides the U.S.: the European powers of Germany, France, and the UK. Those countries can theoretically outmatch Russia in terms of both population and manufacturing, even if Russia gets Chinese help. And the UK and France have nukes of their own. And there’s no loose cannon like North Korea in the neighborhood.
The main danger for Poland is that Germany, France, and the UK, like America, will remain mired in political paralysis, and that their defense-industrial bases will remain moribund, and that they will fail to come to Poland’s aid against Putin.
Even if its manufacturing base allowed Poland to hold out against Russia by itself, a non-nuclear Poland might be cowed into submission by Russian nuclear threats. If West Europe allows Ukraine to fall, Poland will almost certainly strongly consider scrambling for nukes.
So for Japan, South Korea, and possibly Poland, getting nukes is the obvious strategy for dealing with the expansionist empires next door. If these countries went nuclear, it would draw “hard boundaries” past which Xi and Putin could not pass, even if they succeeded in gobbling up Ukraine, Taiwan, and other small nations in the area.
Japanese, South Korean, and Polish nukes would freeze the battle lines of Cold War 2, potentially stopping it from turning into World War 3.
Nuclear weapons have restrained conflict in South Asia
Of course, as I mentioned, Japanese, South Korean and Polish nukes could also start World War 3, in case of an accidental launch. And some people might worry that if they possessed nukes, these three countries would themselves become more aggressive.
In the case of Japan and South Korea, I’m not so worried. These are peace-loving, non-expansionist countries with zero interest in starting wars with their neighbors. Furthermore, they would not be able to win a nuclear confrontation with China, only to make China pay a very high price for any victory. So even if they wanted to be aggressive, they couldn’t.
And both Japan and South Korea are known for highly competent civil servants and well-functioning national institutions; the danger of accidental launch isn’t zero, but it’s probably less than for the US, China, Russia, or other existing nuclear powers.
I can’t think of any countries on the planet more capable of maintaining a nuclear deterrent safely and using it wisely. I have a bit less confidence in Poland, since it escaped communism and endemic corruption only recently, and its technocratic elite has been in power for a far shorter time.
But there’s another reason I’m not so worried about Japanese or South Korean nukes, which is that nuclear deterrence seems to have had a salutary effect on war in South Asia. India and Pakistan have fought each other four times (with India winning all four contests).
Their fourth war, the Kargil War of 1999, came right after both had developed nuclear weapons. But although there were some nuclear threats, the nuclear factor is part of what made Pakistan eventually back down. Ultimately, casualties in that war were very low — probably less than 2000 deaths all told.
An India-Pakistan standoff in 2019, meanwhile, fizzled in part because of worries over nuclear weapons. Pakistan’s President Imran Khan famously declared: “With the weapons you have and the weapons we have, can we afford miscalculation? Shouldn’t we think that if this escalates, what will it lead to?” Ultimately, both countries backed off of hostilities.
This is a very encouraging outcome. India and Pakistan are much poorer countries than Japan or South Korea, and have a recent history of warfare. And yet nuclear weapons very clearly acted as a restraint on war between the two bitter enemies. Obviously, the possibility of a nuclear war between the two remains, and people are right to be scared of it.
But South Asia offers a glimmer of hope that nuclear deterrence can stop or prevent conventional war between major powers, just as it stopped the superpowers from going to war with each other during the first Cold War.
Where does nuclear proliferation stop?
So while I think Japan and South Korea getting nukes would reduce the risk of major conflict, there’s one more issue to consider: Where does it end? Every instance of nuclear proliferation prompts other countries to think “Why not us, too?”.
If Japan and South Korea get nukes, why not Indonesia, Vietnam, and Malaysia? If Poland gets nukes, why not Hungary, Armenia, or Azerbaijan? A world where every country has nuclear weapons will almost certainly see them used at some point, after which their use could become normalized.
What we need in order to prevent this is a strict internationally enforced nuclear nonproliferation regime. Right now, we don’t have that; China and Russia are happy to help Iran and North Korea thrive under US sanctions, allowing their nuclear programs to continue.
What we have right now is a unilateral nonproliferation regime, where Chinese and Russian allies get nukes, and U.S. allies don’t. This is kind of like trying to implement gun control by giving up your guns and expecting your enemies to follow suit.
The only global nuclear nonproliferation regime that will work is one that China and Russia both buy into wholeheartedly and work to enforce. And they will only do that if they see a threat of proliferation on the opposite side of the global divide. Right now, China and Russia have no incentive to enforce nonproliferation, because they know US allies will refrain from getting nukes unilaterally and voluntarily.
If Japan and South Korea go nuclear, this immediately changes. At that point, China and Russia know that democratic countries are going to play by the same rules they are, instead of a different, more restrictive set of rules. Which means China and Russia become just as worried about nuclear proliferation as the US and West Europe are.
Right now, Japan and South Korea’s lack of nukes represents a glaring hole in the global balance of power, and an invitation to China and Russia to expand. It may seem paradoxical to think that new countries getting nukes would lead to a fundamentally more secure world, but in this case, I think the alternative is clearly worse.
Notes
1 The non-nuclear Iran, unlike North Korea, has suffered regular Israeli and US attacks. Nuclear Pakistan’s sovereignty is regarded as inviolable. And despite the popularity of “Death to Israel” chants, other Middle Eastern countries don’t seriously think about launching a major war with it, because Israel has nukes.
This article was first published on Noah Smith’s Noahpinion Substack and is republished with kind permission. Become a Noahopinion subscriber here.