Japan and the Unification of Korea: Challenges for U.S. Policy Coordination
NBR Analysis vol. 10, no. 1

Japan and the Unification of Korea
Challenges for U.S. Policy Coordination

by Michael H. Armacost and Kenneth B. Pyle
March 1, 1999

This essay examines the dynamics of Japan’s relations with North and South Korea, the potential role of Japan in unifying the peninsula, and the consequent implications for U.S. policy. Japan has an immense stake in the outcome of unification because it will deeply influence its relations with its closest neighbor as well as with the United States, China, and Russia.

The sudden unanticipated end of the Cold War presented Japan with a new set of foreign policy challenges, among which the prospect of Korean unification is one of the most problematic. In this essay we argue that, although it has critical interests at stake, Japan labors under constraints that make it unlikely to take the lead in resolving the complex issues involved. Rather, it is more likely to be reactive and adaptive to the unification process, accommodating to the changing circumstances of unification in a cautious and incremental fashion. In some respects, because the nature of reunification is so uncertain in its implications for Japan’s interests, Japanese policymakers may privately prefer a continuation of the status quo of a divided Korea. Nevertheless, Japan cannot afford to resist unification. Moreover, in the potential scenarios for unification that we examine, Japanese cooperation with the United States is essential. American leadership in resolving strategic issues on the peninsula remains indispensable, but successful American initiatives will require skillful policy coordination with Japan that takes account of its ally’s interests and sensibilities. The resources that Japan can bring to bear and the role it plays will go a long way toward determining an enduring settlement on the peninsula and achieving a stable new order in Northeast Asia.

Japan’s Stake in Korean Unification

Japan has an immense stake in the outcome of unification because it will determine the fundamental nature of its strategic relationship to its closest neighbor. As Masashi Nishihara, a leading strategic thinker at Japan’s National Defense University, sums up, “Japan seeks a united Korea that is friendly to Tokyo and Washington, that is economically viable and politically open, and that will allow token U.S. presence to remain.” [1] A unified Korea that retains nuclear weapons, is tilted toward China, refuses to countenance a continued security relationship with the United States that includes some continuing American military presence, and/or is resolutely hostile toward Japan in its vision of the future would represent a major foreign policy defeat for Japan and a problem of immense concern for the nation’s future. A reunified Korea with renewed animus toward Japan would have long-term, unfavorable implications for Japanese security. ”

In addition to the strategic relationship, Japan’s commercial interests will also be deeply affected by the outcome of the reunification process. Despite prolonged political bitterness between Japan and the Republic of Korea (ROK) since World War II, the two countries…

[1] Masashi Nishihara, “Japan’s Receptivity to Conditional Engagement,” in Weaving the Net: Conditional Engagement with China, edited by James Shinn, Council on Foreign Relations, 1996, p. 187.