This chapter provides a framework for understanding why states promote regional security multilateralism. It defines several types of security multilateralism, including collective security, common security, cooperative security, and security communities, and the utility these types of security multilateralism provide by helping member states reduce the risk of accidental war and arms races, and by facilitating cooperation on common security goals, especially in nontraditional security areas such as counterpiracy and Humanitarian and Disaster Relief (HaDR). It also provides a narrower explanatory framework tailored to state interests that focuses on the value of regional security multilateralism for reassuring others about the state's disposition as a military power, ameliorating the state's alliance security dilemma, and providing security utilities that are otherwise difficult to provide. Additionally, it explains the role of policy entrepreneurs in promoting policy change.

This chapter analyzes Japan's strategy of regional security isolationism during the Cold War, which attempted to address two overall concerns: how to reassure its neighbors that it would not again emerge as a military threat, and how to avoid entrapment in US regional wars and military strategy. Japan maintained a low security posture that avoided any security engagement with its neighbors, with Japan even refusing to discuss security, in order to promote reassurance. The sole exception to its security isolationism was its alliance with the US, but Japan used its security isolationism and low security posture to successfully resist US efforts to involve it in US regional wars and strategy. Later in the Cold War, Japan followed the US in rejecting un-like-minded regional security multilateralism because of Soviet support for the idea. Japan institutionalized its security isolation through the Fukuda Doctrine's promise not to become a military power.

This chapter examines Japan's rethinking of its regional security isolationism as a result of the end of the Cold War. The declining Soviet threat, growing US-Japan economic tensions, and tensions over Japan's response to the Gulf War caused Japanese security intellectuals and diplomats to begin questioning the continued viability of security isolationism, especially as Soviet decline and the relative US decline caused Japan to loom ever larger as a potentially dominant regional actor and even military power. US pressure on Japan to expand its security role beyond territorial defense and send the SDF to the Middle East before, during, and after the Gulf War convinced Japanese policy makers that Japan needed to beginning playing an international security role beyond its borders, beginning with an SDF dispatch to Cambodia to participate in a UN Peacekeeping mission there.

This chapter reveals the policy-making process behind Japan's first postwar regional security initiative, the Nakayama proposal. It shows that abandoning regional security isolationism and providing an expanded reassurance framework to match Japan's expansion into international security, starting with participation in UN Peacekeeping, was the primary motivation behind the Nakayama proposal. Helping keep the US engaged in East Asian security was a secondary motivation, as was preventing the Soviet Union or another country from defining regional security multilateralism in a way that did not match Japan's interests. For these purposes, Japan designed a proposal for creating a like-minded regional security dialogue of US allies and leaning states that shared the same ideology and economic systems. This policy process initially involved collaboration with ASEAN-ISIS, although ASEAN-ISIS sought to create a broader un-like-minded multilateral forum. Japan also developed an alternative to CBMs, mutual reassurance measures (MRMs).

This chapter examines the final version of the Nakayama proposal presented by Foreign Minister Nakayama at the 1991 PMC, which called for creating a regional multilateral security forum, and which Japan would use in part to reassure its neighbors about its security policy. This chapter also analyzes negative reactions to the Nakayama proposal from several ASEAN states, most notably Indonesia and the US, and Japan's persistence in defending and promoting the proposal in the face of this opposition. It shows that Japan eventually succeeded in persuading the US to reverse its opposition to regional security multilateralism. Moreover, ASEAN, at its fourth summit meeting in early 1992, adopted one part of the Nakayama proposal—namely, the creation of a security dialogue in the PMC—even while not adopting the proposal to create a Senior Officials' Meeting (SOM).

This chapter examines follow-up initiatives to the Nakayama proposal that Japan launched in 1992–93, following the Fourth ASEAN Summit, and behind-the-scenes negotiations between Japan and ASEAN culminating in the establishment of the ARF in July 1993. Japan's initiatives resulted in part from fragmentation of the policy process as Prime Minister Miyazawa and some within MOFA, notably Satoh Yukio and the Asian Bureau, favored Japan proposing a broader un-like-minded regional multilateral security forum that would, unlike the PMC security dialogue, include China and Russia, while others within MOFA, notably the hard-line Russian Desk, opposed including especially Russia in a regional forum. Major Japanese initiatives include Miyazawa's speeches in Washington at a CSIS gathering, and in Bangkok and his advisory council on Japan's relations with its Asian neighbors. Japan's proposal to add security to the agenda of the Japan-ASEAN Forum was another important initiative.

This chapter traces Japan's steady support for regional security multilateralism from the establishment of the ARF in 1994 until 2000. It demonstrates that Japan assumed a leadership role in promoting CBMs through the ARF, especially defense-paper transparency. Additionally, Japan originally wanted to maintain the PMC as a like-minded multilateral security forum that would complement, if not supervise, the ARF, but ASEAN defied Japan's expectations and admitted China, Russia, and India into the PMC beginning in 1996, ending the "like-minded" nature of the PMC. Japan responded with the Hashimoto Doctrine to establish a Japan-ASEAN security forum and an annual summit, reestablishing Japan's special relationship with ASEAN dating from the Fukuda Doctrine. ASEAN accepted Hashimoto's ASEAN-Japan summit proposal, but broadened it to include China and South Korea, thereby establishing the ASEAN Plus Three (APT). This chapter also traces US suspicion of Japan's promotion of regional security multilateralism.

This chapter challenges the literature claiming that Japan lost interest in regional security multilateralism by the turn of the century. It demonstrates that Japan continued to champion regional security multilateralism, using the ARF as a platform to promote consensus for establishing the first regional multilateral security institution dedicated to combating piracy, the Regional Cooperation Agreement on Combating Piracy and Armed Robbery Against Ships in Asia (ReCAAP). Japan promoted the establishment of a regional multilateral defense ministers' forum, aided the establishment of the ADMM-Plus in 2010, and successfully proposed the establishment of EAMF in 2012. In Northeast Asia Japan built on the APT to promote trilateral cooperation with China and South Korea, including security cooperation. This chapter shows that despite Prime Minister Abe's known support for minilateralism among US allies and leaning states, even he has continued Japan's policy of promoting regional security multilateralism in the Indo-Pacific region.