Should Washington Close Its Nuclear Umbrella Over South Korea and Japan?

Donald Trump again is causing international consternation. His remarks about South Korea and Japan developing nuclear weapons set off a minor firestorm.

“It would be catastrophic were the United States to shift its position and indicate that we support somehow the proliferation of nuclear weapons to additional countries,” argued deputy national security adviser Ben Rhodes.

Actually, what would be catastrophic is American involvement in a nuclear war as a result of its defense commitment to another nation, especially one able to defend itself.

Neither country pays enough for its own protection, instead preferring to rely on Washington. The issue of one of them going nuclear “at some point is something that we have to talk about,” he explained.

That’s hardly a radical sentiment. The issue recently was raised by a former presidential candidate in South Korea. After Trump’s remarks Cheong Seong-chang of the Sejong Institute observed: “If we have nuclear weapons, we’ll be in a much better position to deal with North Korea.”

Over the years there has been talk in Japan about pursuing the nuclear option. Former Osaka Mayor Toru Hashimoto said Trump’s sentiments allowed “Japan to change the peace-addled notion that America will protect us.”

Despite the campaign to treat nuclear nonproliferation as sacrosanct, it cannot be decided in isolation. Broadly speaking, it is better if fewer nations have nukes.

Yet in some cases proliferation might be stabilizing. Had Ukraine not given up its nuclear weapons left over from the collapse of the Soviet Union, Russia might not have grabbed Crimea.

Worse, the way Washington won assent of some nuclear-capable powers to abstain is to provide a “nuclear umbrella,” that is, promise to use nukes to defend them if necessary. As a result, the price of nonproliferation in East Asia is America’s willingness to risk Los Angelas to protect Seoul and Tokyo, and maybe Taipei and Canberra too.

Today nonproliferation means only the bad guys get guns. In East Asia China, Russia, and North Korea are the nuclear powers. America is supposed to provide geopolitical balance.

The result of this situation truly could be catastrophic.

So far, America’s defense promises have not created stability. China is acting aggressively toward Japan, Philippines, and Vietnam in particular; Russia has challenged the U.S. in the eastern reaches of Europe and the Middle East. North Korea is worse, constantly breathing fire against its neighbors and the U.S.

Still, policymakers act as if U.S. defense guarantees will never get called. The threat of nuclear retaliation undoubtedly has deterrent value. However, the two great wars of the 20th century started because deterrence failed.

In particular, threats which seem inconsistent with underlying interests have little credibility. Thus, the Chinese have publicly doubted that America would risk nuclear war over Taiwan’s independence.

Moreover, once given, it is hard to back away from security commitments which have lost their original purpose. Which means if deterrence fails America could be at war automatically, without considering the stakes.

Finally, promising to defend other, smaller powers allows them to hold American security hostage. With Washington behind them they are more likely to engage in risky behavior. During the 2000s Taiwan’s independence-minded Chen Shui-bian upset Chinese sensibilities.

Washington’s view that they are covered by the “mutual” defense treaty likely has encouraged Tokyo to refuse to even discuss the status of the Senkaku/Diaoyu Islands with China. Philippines is attempting to enlist the U.S. in its squabble with Beijing over Scarborough Reef.

America’s nuclear umbrella deserves scrutiny and a serious debate. Yet Rhodes dismissed even discussing the idea, contending that “for the past 70 years” the U.S. has opposed nuclear proliferation. But when the world changes, policy also should change. As I pointed out in National Interest: “The greatest risk of catastrophe for this nation would be sleep-walking into an Asian nuclear war.”