“Japan, South Korea, and the United States Nuclear Umbrella: Deterrence After the Cold War” by Terence Roehrig


The principal argument of Terence Roehrig’s new book is that the United States will not and should not use nuclear weapons to defend Japan or South Korea. The US nuclear umbrella, he contends, has been little more than a bluff because the threat to use nuclear weapons, even in response to a nuclear attack, is not credible or necessary.

This may come as a surprise to Japanese and South Korean leaders and citizens who have relied on the guaranty of the US nuclear umbrella for seven decades. More surprising still is that the author is not a pacifist, but a professor at the US Naval War College and the director of that institution’s Asia-Pacific Studies Group.

Roehrig recounts the history of US extended deterrence as applied to Japan and South Korea from the end of World War II to the present. Nuclear weapons, both strategic and tactical, were central to defending both countries during the Cold War. Indeed, Roehrig notes that President Eisenhower used the threat of nuclear weapons to end the Korean War. In fact, Eisenhower’s general policy of extended deterrence relied on the threat of “massive retaliation” with nuclear weapons.

Extended deterrence also included positioning nuclear forces in Japan and South Korea. The United States maintained nuclear forces on Okinawa until the island reverted to Japan in 1972. It also likely placed nuclear weapons at several airbases in Japan, and US warships with nuclear weapons regularly visited Japanese ports. “Japan,” Roehrig writes, “became a major logistics hub for U.S. nuclear weapons in Asia.”

Meanwhile, from the late 1950s to the early 1990s, South Korea hosted between 250 and 600 US tactical nuclear weapons, including, Roehrig notes, “nuclear-tipped missiles …, nuclear artillery munitions, atomic demolitions mines, and gravity bombs.” President George HW Bush in 1991 began to remove US nuclear weapons from South Korea in an effort to encourage North Korea to abandon its nuclear ambitions. That and subsequent efforts to entice North Korea’s leaders to forego the development of nuclear weapons failed miserably.

Roehrig notes that Japan and South Korea welcomed the protection of the US nuclear umbrella, and have repeatedly sought reassurances from US leaders about its continued operability. Without the US nuclear guaranty, both countries might have developed their own nuclear force, as France did in the mid-1960s. Roehrig sees this non-proliferation effect of the nuclear umbrella as one reason to continue the nuclear bluff. The other reason is that it sends an “important political signal that is an integral part of the regional security architecture and helps demonstrate the US commitment to its allies in Asia.”

A bluff is not an important political signal; it is a bluff.

Japan, South Korea, and the United States Nuclear Umbrella: Deterrence After the Cold War, Terence Roehrig (Columbia University Press, September 2017)
Japan, South Korea, and the United States Nuclear Umbrella: Deterrence After the Cold War, Terence Roehrig (Columbia University Press, September 2017)

This is where Roehrig’s argument breaks down. A bluff is not an important political signal; it is a bluff. The nuclear umbrella worked during the Cold War because potential adversaries—the Soviet Union, China, North Korea—and US allies in Europe and Asia believed that the US promise to defend its allies with “all means necessary”, including nuclear weapons, was not a bluff. Roehrig recognizes that one doesn’t need certainty for deterrence to work, but advocating that the US never use nuclear weapons under any circumstances on behalf of its Asian allies undercuts the ambiguity that he believes sustains the nuclear bluff.

Roehrig’s argument is reminiscent of the McGeorge Bundy-George Kennan-Gerard Smith-Robert McNamara article in Foreign Affairs in 1982, advocating “no first use” of nuclear weapons for NATO. Fortunately, the Reagan administration ignored the advice of these “wise men”, NATO and US-Asian allies stood firm, and the Soviet empire collapsed.

To be sure, Roehrig sees continuing value in extended deterrence for Japan and North Korea, but his version of extended deterrence uses precision-guided conventional weapons, ballistic missile defense, and nuclear bluff. The US, he writes, should never use nuclear weapons even if its Asian allies are attacked with nuclear, biological, and chemical weapons. As he writes:


Nuclear use in Asia would have a catastrophic effect on civilian populations, and the effects would be likely to spread throughout the  region, causing horrendous damage to enemies and allies alike. Moreover, US nuclear use, even in retaliation, weakens norms against their use in future conflicts and makes it easier for other states to cross that redline, which is not in anyone’s interest.


Perhaps one reason for Roehrig’s anti-nuclear version of extended deterrence is his belief, expressed many times in the book, that there is little likelihood of North Korean or Chinese aggression against US allies in Asia. This prediction will likely provide little comfort to Japan or South Korea, or to the thousands of US forces stationed in those countries who expect the protection of the American nuclear umbrella.

Roehrig is not shy about expressing his moral revulsion at the potential use of nuclear weapons by the United States in defense of its allies. But there is nothing moral about weakening deterrence against potential enemies who threaten our allies in Asia or elsewhere. As the brilliant nuclear strategist Albert Wohlstetter wrote at the height of the Cold War:


In a war, when all alternatives may be extremely risky to an adversary, we may not convince him that the alternative of nuclear attack is riskier than the others if we have persuaded him also that it can be done safely because we won’t retaliate for fear of the unlimited harm we would bring on ourselves. We only complete the absurdity and undermining of deterrence when we say that we have no intention to fight, that is, to use nuclear weapons if deterrence fails. Unfortunately, the principle of deterrence and the principle of “Use, Never” mutually annihilate each other.

Francis P Sempa is the author of Geopolitics: From the Cold War to the 21st Century and America’s Global Role: Essays and Reviews on National Security, Geopolitics and War. His writings appear in The Diplomat, Joint Force Quarterly, the University Bookman and other publications. He is an attorney and an adjunct professor of political science at Wilkes University.