By Joshua Chang —

Service members with the Japan Self Defense Force approach King’s Beach during a simulated reconnaissance mission of exercise Talisman Sabre 19 in Bowen, Australia, July 21, 2019. Source: U.S. Marine Corps photo by Lance Cpl. Tanner D. Lambert, U.S. Government Work.
Recent discourse on U.S. policy in Asia has focused on Japan’s contributions to Indo-Pacific security amid calls for U.S. allies to increase their role in regional defense. Japan supports the Indo-Pacific security architecture through its Self-Defense Forces (SDF) and has taken several steps in recent months that demonstrate its status as an important contributor to Indo-Pacific security despite some constraints. Tokyo’s recent contributions to East Asian security architecture, including efforts to strengthen the U.S.-Japan alliance, participation in multilateral military exercises, and the SDF’s growing operations outside of Japanese territory, provide the underpinning for an expanded regional role. Japan’s contributions highlight its serious commitment to its own national defense and security cooperation with the United States and other regional partners.
Historically, two main limitations have inhibited Japan’s participation in regional security: legal mandates and budgetary concerns. Legal constraints handicap the SDF’s use of force under Article 9 of the postwar constitution, which calls for Japan to give up war as a tool of statecraft. Over the years, however, Japanese lawmakers have reinterpreted this clause to give more flexibility to the SDF, most recently in 2015 with the passage of legislation authorizing the exercise of collective self-defense in certain circumstances. Limits on defense spending, capped unofficially at one percent of gross domestic product, also prove challenging for the SDF. However, Japan’s recent passage of a five-year defense spending plan and Prime Minister Shinzo Abe’s recent victory in parliamentary elections suggests Tokyo will remain committed to increased defense spending over the next few years.
Changing geopolitical dynamics in Asia have prompted Japan to create close links with other like-minded partners in part to counter China’s rise. Recent procurement, participation in military exercises, and capacity-building initiatives in the region all reflect Japan’s continuing contributions to Indo-Pacific security.
In the area of procurement, Japan has decided to purchase an additional 105 F-35 fighters from the United States and equip at least one of its two Izumo-class destroyers with the ability to launch the short takeoff and vertical landing (STOVL) variant of these aircraft. Tokyo also commissioned its second anti-submarine warfare (ASW) destroyer, Shiranui, and its 10th Soryu-class attack submarine, SS 510. These acquisitions are a few examples of how the SDF is modernizing its forces to meet a wide array of threats, and Japan’s commitment to enhance its defense capabilities supports U.S. strategy in Asia centered on close cooperation with allies and partners.
Another way that Japan is contributing to the Indo-Pacific security architecture is its involvement in military exercises, which have showcased Tokyo’s military capabilities and increased the readiness of its forces. In May 2019, Japan’s Maritime Self Defense Forces (MSDF) participated in naval maneuvers alongside the Australian, South Korean, and U.S. navies in the Pacific Vanguard exercises. A month later, three MSDF vessels, Izumo, Murasame, and Akebono, took part in U.S.-led naval exercises in the South China Sea, where the Izumo brought along an amphibious infantry brigade unit for the first time. From July 11-24, 2019, the MSDF participated for the first time in the Talisman Sabre exercise alongside U.S. and Australian forces.
Japan has also underscored its increased leadership role in regional security through cooperation with other countries in the region. During the G20 summit in Osaka in June 2019, Prime Minister Abe and Indian Prime Minister Narendra Modi agreed to step up high-level defense dialogues between their countries and reaffirmed their support for a Free and Open Indo-Pacific. (Japan has engaged in the Malabar naval exercise with India and the United States since 2015, when it switched from an observer state to a formal participant.) Japan has also engaged countries in Southeast Asia such as Vietnam, where the Izumo and Murasame visited in June 2019 and conducted bilateral exchanges with members of the Vietnamese defense community.
On a capacity-building level, Tokyo has made major contributions to humanitarian assistance and disaster relief (HADR) operations in Southeast Asia. For the past five years, Japan has pledged 300 billion yen annually to the Association of Southeast Asian Nations (ASEAN) to build disaster-mitigation capability and offered guidance on humanitarian assistance strategies. Moreover, Tokyo has reinforced its continued commitment to HADR this year with its 2nd Japan-ASEAN Invitation Program on Humanitarian Aid and Disaster Relief, where SDF and ASEAN military delegates met to discuss cooperation in this area.
Despite legal and budgetary constraints, Japan’s Self Defense Forces are engaged in a wide variety of activities demonstrating the country’s role as a significant contributor to Indo-Pacific security. Tokyo continues to acquire additional equipment to boost its military capabilities and participate in joint exercises and capacity-building with other regional partners. Based on these current trends, Japan’s role as a proactive security contributor can be expected to increase in cooperation with the United States and other like-minded countries.
Mr. Joshua Chang is a research intern with the Japan Chair at CSIS and a master’s student at the Walsh School of Foreign Service, Georgetown University.
Excellent. A well-written and well-researched article that was easy to understand for someone not as versed in the subject matter.