The nuclear balance of power in Northeast Asia is in crisis. North Korea, China, and Russia are using their nuclear arsenals as cover to undermine the regional order. Meanwhile, South Korea and Japan must rely on the promise of U.S. extended nuclear deterrence commitments that can only be called upon in the event of nuclear war and which are otherwise ineffective at stopping the current nuclear arms race. Given the emerging Eurasian nuclear axis, it is time to explore similar collective countermeasures among U.S. allies. In the 1960s, the United States deployed over 2,000 non-strategic nuclear weapons, commonly known as tactical nuclear weapons, in both South Korea and Japan. This was to deter conventional military threats from China and North Korea, long before they had their own nuclear weapons, in addition to the Soviet Union. Now that there are three nuclear threats in Northeast Asia, it is time to restore the U.S. nuclear force posture to reflect the threats of the 2020s. The redeployment of U.S. tactical nuclear weapons to South Korea and Japan would represent a third way between the risky pursuit of an indigenous nuclear weapons capability by these countries and the current dependence on offshore U.S. strategic weapons.

Introduction

Cold War Lessons and Commitments

The North Korean Nuclear Threat

The Eurasian Nuclear Axis

Shifting South Korean and Japanese Attitudes

The Lesser of Two Evils