Introduction—Japan Seeks “Networking” with Regional Allies
In early May 2019, Japanese Foreign Minister (FM) Taro Kono tweeted support for Taiwan’s bid to attend the World Health Assembly as an observer—thereby advocating for Taiwan’s return to a status it previously held from 2009 until 2016, when the World Health Organization ceased inviting Taiwan at the request of the People’s Republic of China (PRC) (Twitter, May 7; Focus Taiwan, May 8). While Taiwan has long enjoyed U.S advocacy for limited participation in some international organizations, Kono’s tweet represented the first time that Japan has explicitly voiced similar endorsements in the face of PRC objections (Japan Times, May 8).
This development is only the latest in a recent trend of increasing Japanese support for Taiwan’s international presence. For example, Japan has also formally endorsed Taiwan’s bid to join the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP) trade agreement, and has reportedly been considering establishing a formal security dialogue with Taiwan’s government (Taipei Times, February 19; Taiwan News, March 5). However, improving relations with Taiwan also carries the necessary corollary of worsening relations with the PRC. While Japan and the PRC approached a tentative rapprochement in 2018 around the fortieth anniversary of the Treaty of Peace and Friendship, and while Japanese Prime Minister Abe Shinzo continues to describe Sino-Japanese relations as “fully returned to their normal path,” underlying tensions driven by territorial disputes and a growing military imbalance remain unresolved (China Brief, May 31, 2018; Abe Shinzo, January 28).
Such is the context in which Japan-Taiwan relations should be understood: Japan faces an increasingly aggressive PRC, and is therefore seeking increasing cohesion between U.S. allies and partners in the Indo-Pacific as a key pillar of its foreign policy. This is a process that Japan’s foreign minister has called “networking” (Taro Kono, January 28). Japanese networking is typically defined as a policy of enhancing Japan’s security cooperation alongside other nations within the American hub-and-spoke network of bilateral military alliances in the Pacific (Asan Forum, February 2016). 
Japan’s latest Diplomatic Bluebook describes the policy as reinforcing the U.S.-Japan “alliance network by strengthening multilayered cooperative relationships with allies and partners, with the Japan-U.S. Alliance as the cornerstone,” and further notes that Japan has for several years also pursued such a relationship with Australia and India (Ministry of Foreign Affairs (Japan), October 1, 2018). This has been further underpinned by a reaffirmed U.S. partnership with Taiwan and unabated military tensions with the PRC. Japan appears to be explicitly improving bilateral ties with Taiwan in non-security capacities, while debating the potential role of the island state as a potential partner for “networking” in regional security.
Japan Considers Security Networking with Taiwan
Japan’s networking in pursuit of a favorable security environment does not necessarily mean a narrow focus on security dialogues or joint military exercises. Cultural, ideological, and political values matter in securing partners against an authoritarian PRC, and deepening ties with allies can reflect and reinforce these shared values even without explicit security cooperation. FM Taro Kono’s speech at the opening of the 198th Session of the Diet presented an expansive scope for networking: one in which Japan will seek to improve ties not only with “countries sharing strategic interests,” but also with “countries that share common values” including “democracy, basic human rights, the rule of law and respect for international laws” (Taro Kono, January 28).
Due to the complex nature of Japan-PRC relations, Japanese networking with Taiwan has not yet reached the level of overt security cooperation. Much as the U.S. has reaffirmed its commitment to Taiwan without exceeding the terms of the Taiwan Relations Act (TRA),  the government of Prime Minister Abe has maintained an official policy of keeping Japan-Taiwan relations at the non-governmental level, pursuant to the 1972 Japan-China Joint Communique (Ministry of Foreign Affairs (Japan), October 1, 2018).
For its part, the administration of Taiwan President Tsai Ing-wen (蔡英文) has openly advocated for establishing quasi-official ties beyond the 1972 restrictions. President Tsai explicitly called for official dialogue on Japan-Taiwan security cooperation in an early March interview with The Sankei Shimbun (Sankei Shimbun, March 3). More specifically, Taiwan’s de facto ambassador to Japan Frank Hsieh (Xie Changting, 謝長廷) and Tsai herself have publicly sought Japanese support for Taiwan’s joining the CPTPP, and for formalizing relations between the two nations. Hsieh has also called on Japan to adopt the long-discussed “Basic Law on Japan-Taiwan Relations” (Ri-Tai Jiaoliu Jibenfa, 日台交流基本法), commonly considered a Japanese version of the American TRA (Epoch Times, January 29).
Tsai’s and Hsieh’s economic appeals have been generally well-received: Japan officially welcomed Taiwan’s bid to join the CPTPP, and is entertaining unofficial proposals to offer Taiwan broader diplomatic support in exchange for Taiwan’s commitment to end its ban on importing food from Japan’s Fukushima region (Taiwan News, May 3; Taiwan News, May 8). However, Japan did not affirm Tsai’s call for an official security dialogue, and quietly declined through unnamed sources in PRC and Taiwanese newspapers without issuing a formal statement (Focus Taiwan, March 5).
Despite this avoidance of any formal commitments, Japan may in fact have already begun discreet networking operations: for example, Taiwan’s indigenous submarine industry, the development of which has been a longstanding priority of Tsai Ing-wen and her political party, has reportedly received unofficial support from Japanese experts. Further, current models for Taiwan’s indigenous defense submarines conspicuously resemble Japan’s Soryu-class submarines, suggesting more significant Japanese involvement than has been officially revealed (SCMP, July 14, 2018; New Frontier Foundation, March 2014; Taiwan News, August 21, 2018; Shephard News, May 10, 2019; Kyodo News, May 9, 2019). The salient question is not whether Japanese interest in formal Japan-Taiwan security cooperation exists; rather, it is whether and how this interest can evolve from discreet support to national policy in the face of determined opposition from Beijing.
Japan’s soft rejection of Tsai’s dialogue request was a move intended to keep Tokyo’s options open, while avoiding embarrassment for Taipei. However, ever-rising aggressions from Beijing could lead to a growing openness in Tokyo to some sort of security cooperation akin to the TRA. Moreover, the increasing prominence of Japanese public officials calling for precisely such an agreement indicates growing support for the idea in Japanese domestic politics.
A Basic Law for Japan-Taiwan Relations
Consistent with the broader logic of networking, the political drivers for adopting a Basic Law for Japan-Taiwan Relations have been overwhelmingly focused on forming a geopolitical coalition able to resist the growing political and military influence of the PRC. Three Japanese public figures have emerged as strong proponents of enhanced Japan-Taiwan security ties: Takei Tomohisa, Suzuki Keisuke, and Nagashima Akihisa.
In 2018, retired Admiral Takei Tomohisa, a former Chief of Staff of Japan’s Maritime Self-Defense Force (MSDF) and a longtime observer of Chinese advances in naval power, began to advocate for the establishment of formal communication mechanisms between the Japanese MSDF and Taiwanese naval forces in order to “resist” expanding PRC military power and its potential to “change the status quo in the region” (Epoch Times, May 3, 2018; The Japan Times, July 30, 2015). Takei compared this proposed mechanism to the emergency communication system in place between Japan and the PRC to avoid accidental collisions and escalations between Japanese Self-Defense Forces (SDF) and the People’s Liberation Army (PLA). The Sino-Japanese variant was established to alleviate tensions resulting from PLA jets approaching Japan-claimed airspace and SDF jets scrambling to intercept; by contrast, a similar mechanism linking the SDF and Taiwan’s military would be a transparent networking of regional militaries balancing against the PLA (Mainichi, June 8, 2018; Asahi Shimbun, June 8, 2018).
Suzuki Keisuke, a member of PM Abe’s Liberal Democratic Party and Ranking Member of the Committee on Foreign Affairs in the House of Representatives, has similarly raised the specter of the PLA threat in order to urge formal Japan-Taiwan security cooperation (Suzuki Keisuke, undated). Since 2016, Suzuki has repeatedly emphasized the threat posed by a modernizing and increasingly aggressive PLA—and by extension, the need for Japan to take measures to form a military coalition able to check PLA expansion (Japan Times, December 14, 2016). Suzuki has also identified Chinese Communist Party (CCP) influence in Taiwan’s democracy as a critical national security threat for Japan. Pointing to the slow erosion of democratic norms and civil rights in Hong Kong, and concerned that similar developments in Taipei could presage an adverse security environment for Japan, Suzuki has repeatedly but cautiously advocated for a Japanese version of the TRA to secure Taiwan’s political independence (Epoch Times, April 19; Epoch Times, April 20; The Japan Times, December 14, 2016). This year, Suzuki publicly hinted at the possibility that he would draft a Japanese TRA bill for introduction in the Diet (Liberty Times, April 19; Taiwan News, April 19).
Nagashima Akihisa, an independent member of the House of Representatives and a longtime fixture of the Japanese foreign policy community, has long advocated increased Taiwanese military capabilities in order to check the PLA (Nagashima Akihisa, undated). Nagashima has called for a Taiwanese military buildup, as well as closer military coordination between Taiwan and American allies in the Western Pacific (Taipei Times, September 17, 2017). Nagashima is also a fixture at the newly-formed Japan-US-Taiwan Relations Institute (JUST), which advocates for Taiwan’s inclusion in multilateral humanitarian assistance and disaster relief partnerships, as well as in a possible Oceanic Security Alliance (Haiyang Anbao Lianmeng 海洋安保聯盟) (Central News Agency (Taiwan), December 3, 2018). Though Nagashima and JUST have distinctly multilateral visions for Taiwan’s international presence beyond the Japan-Taiwan bilateral relationship, both champion a Basic Law for Japan-Taiwan Relations as an initial effort.
While it remains unclear whether passage of a Basic Law or any comparable corollary for the TRA is viable in Japan, there exists growing support for increased Japan-Taiwan engagement. Divergent agendas related to Taiwan cover a broad spectrum: ranging from a proposed bilateral relationship, to strict military-to-military agreements, to a Japanese TRA, to Taiwan’s integration into a formal security alliance. However, all of these approaches share common assumptions: that the PLA is a rising military threat; that Japan must act to form a coalition counterbalancing the PLA; and that Taiwan is a critical potential partner in this effort.
Formally engaging Taiwan in naval affairs would be a daring gambit: joint Japan-Taiwan maritime cooperation could geographically constrain Chinese power projection within the First Island Chain and facilitate joint operations necessary for a possible archipelagic sea denial strategy. It is also likely to significantly increase tensions with Beijing and to precipitate an escalation in current cost-imposition pressures (Taipei Times, September 17, 2017; CSBA, February 15, 2015). However, if Beijing maintains its current trajectory of aggressive maritime behavior in the East China Sea, then it may drive Tokyo toward further “networking” with Taiwan.
Howard Wang is the China Program Assistant at The Jamestown Foundation. He received his MPP from the Georgetown University McCourt School of Public Policy.
 Wang Dong, “Two Asias? China’s Rise, Dual Structure, and the Alliance System in East Asia” in Strategic Adjustment and the Rise of China: Power and Politics in East Asia eds. Robert S. Ross & Oystein Tunsjo. (Ithaca: Cornell University Press, 2017) pp. 101.
 The Trump Administration and 116th Congress have reinforced U.S. commitments to Taiwan’s security with a new round of arms sales and partial passage of the Taiwan Assurance Act—actions that signal Taiwan’s status as a strategic partner to the United States, and one with whom Japan might pursue closer ties (SCMP, April 16; Taipei Times, May 9). The Taiwan Assurance Act of 2019 was passed in the U.S. House of Representatives on May 7, 2019, but has not received a vote in the U.S. Senate. See: House Resolution 2002—Taiwan Assurance Act of 2019, Congress.gov. https://www.congress.gov/bill/116th-congress/house-bill/2002.