South Korean President Lee Myung-bak made an unprecedented trip on August 10 to an islet whose sovereignty is disputed by Japan. Lee’s visit—the first by a South Korean president—to Dokdo Island (called Takeshima by the Japanese) was intended to affirm Seoul’s sovereignty in response to perceptions of renewed Japanese territorial claims. Lee’s trip will, however, further inflame already strained bilateral relations with Tokyo.

The deterioration of relations comes at a time when Washington has been urging the two allies to separate contentious historical issues and territorial disputes from strategic policymaking objectives, such as improving deterrence against common threats. The Obama Administration has made strengthening allied military capabilities in Asia an important pillar of American national strategy. Massive looming U.S. defense spending cuts add greater urgency to alliance burden sharing and promoting lateral military efficiencies among allies.

Strained Relations

Japanese Foreign Minister Koichiro Gemba warned that Tokyo would respond firmly to Lee’s trip and that it “would definitely have a large impact” on relations between the two countries. Tokyo lodged strong official protests, postponed the annual bilateral finance minister meeting, called in the South Korean envoy to Japan, and recalled its ambassador from Seoul. The only other time Japan recalled its envoy to Seoul was in 2005 after the ambassador publicly claimed that the islands belonged to Japan.

Lee’s trip comes amid an already tense situation with Japan after the collapse of a proposed bilateral military agreement. In June, Seoul called off the scheduled signing of the accord with Tokyo less than hour before the ceremony due to flaring domestic criticism and legislative backlash over an agreement with South Korea’s former colonizer.

The General Security of Military Information Agreement (GSOMIA) would have been the first military pact between Seoul and Tokyo since the end of Japanese occupation of the Korean Peninsula in 1945. It would have provided a legal framework allowing for the exchange and protection of classified information about North Korea’s nuclear and missile programs, potential military incursions and terrorist or cyber attacks, and China’s increasing military power. The agreement would have improved joint security capabilities and continued nascent efforts to improve bilateral relations.

While Washington has strong relationships with both countries, the third leg of the military triad—that between Seoul and Tokyo—remains virtually non-existent due to bitter historical animosities from Japan’s brutal 35-year occupation of the Korean Peninsula between 1910 and 1945 and territorial disputes. Despite vibrant and far-reaching bilateral economic and trade ties, similar democratic political systems, and shared strategic views of the international order, South Korea and Japan continue to have a strained and tense relationship.

However, Seoul and Tokyo had in recent years taken preliminary steps to improve security cooperation in response to growing concerns over the North Korean and Chinese military threats. The two countries had exchanged observers during military exercises and this summer allowed trilateral participation in what had previously been bilateral exercises with the U.S.

The flare-up of tensions between Seoul and Tokyo has national security repercussions for both countries as well as impeding U.S. security objectives in Asia. The lack of the GSOMIA will prevent Seoul and Tokyo from exchanging information on North Korean and Chinese military developments. The GSOMIA is also necessary for a comprehensive allied missile defense system in Asia. Integrating South Korea, Japanese, and U.S. warning sensors and tracking radars would enhance missile defense security for all three countries.

Washington as Peacemaker

Despite the inherent difficulties in South Korean–Japanese relations, Washington should continue to privately urge both allies to improve ties, including strengthening military cooperation to improve deterrence and defense against common threats. The U.S. should walk a fine line, however, in not appearing to take sides in territorial disputes or becoming embroiled in highly emotional historical issues.

Washington should:

• Publicly emphasize the need to strengthen U.S., South Korean, and Japanese trilateralism for enhancing allied security capabilities.
• Create a Trilateral Security Initiative with an annual 2+2+2 meeting of the three countries’ foreign and defense ministers to develop a joint strategic vision and integrate roles, missions, and capabilities.
• Increase bilateral South Korea–Japan and trilateral South Korea–Japan–U.S. military exercises and maritime security and explore the potential for joint peacekeeping missions, counterterrorism, counter-proliferation, counter-narcotics, anti-submarine warfare, mine-warfare, and humanitarian assistance and disaster response operations.
• Privately urge continued progress toward implementing the South Korea–Japan GSOMIA and logistics sharing agreements.
• Facilitate contact and reconciliation between Seoul and Tokyo but avoid being drawn into serving as a mediator. The U.S. should emphasize achieving mutual objectives by separating current policy issues from contentious historical grudges.
• Encourage South Korea to deploy a multilayered missile defense system that is interoperable with a U.S. regional missile network to provide for a more coherent and effective defense of allied military facilities and the South Korean populace.

Countering Threats Trilaterally

U.S. interests in Asia—ensuring regional stability, protecting maritime freedom of navigation, and peaceful resolution of disputes—benefit from greater multilateral cooperation. Washington should, therefore, exercise leadership by promoting greater military cross-connectivity among U.S. allies and friends to augment traditional “hub and spoke” alliances. Improving South Korean–Japanese cooperation, or at a minimum reducing friction, is important to deterring North Korean and Chinese threats. A strong allied security triad could also form the core group for addressing broader regional issues.

The U.S. will be most effective by maintaining a strong alliance with each ally to allay their individual security concerns about the other. This requires Washington maintaining a strong forward-deployed military presence in the western Pacific and devoting sufficient military resources to remain the guarantor of regional stability.

Bruce Klingner is Senior Research Fellow for Northeast Asia in the Asian Studies Center at The Heritage Foundation.