In an interview with Reuters late last year, Japan Vice Defense Minister Yasuhide Nakayama observed, “There’s a red line in Asia – China and Taiwan.” He added: “How will Joe Biden in the White House react in any case if China crosses this red line? […] The United States is the leader of the democratic countries. I have a strong feeling to say: America, be strong!” The statement’s purpose underscores Tokyo’s security concerns and how Taiwan factors into the US-Japan alliance. The last four years under the Trump administration saw the United States’ engagement with Taiwan increase as China became the primary strategic competitor. In tandem, communications between Washington and Tokyo on related matters have presumably grown. This trend is likely to continue under the Biden administration. Still, was Minister Nakayama’s statement of clarity a sign of one official’s assessment or reflective of an undercurrent in Japanese defense thinking? As Japan continues to express interest in increasing cooperation with Taiwan, cultivating this relationship’s security dimension is critical for all parties involved. The United States-Japan-Taiwan relationship is likely to be a cornerstone of regional security for years to come.
Three Pillars of Japan’s Defense
A reading of recent Japanese official defense policy documents suggests that the senior defense official’s statement may be reflective of the latter proposition. Every year, Japan releases its annual white paper “Defense of Japan.” The 2020 edition dedicated a section to the “Three Pillars of Japan’s Defense,” which are Japan’s defense architecture, the US-Japan alliance, and security cooperation. Together, these pillars represent Japan’s plan to achieve the defense component of its national security.
The first pillar—Japan’s defense architecture—addresses the rapidly changing state of Japanese defense capabilities. Reforms within the last decade emphasize Japan’s current push to modernize its legislation and capabilities. One key part is the 2016 “Peace and Security Legislation,” which bundled together several national security amendments into one law. A notable aspect of this bill allows the Japanese Self-Defense Forces (JSDF) to “provide necessary logistics support and search & rescue to armed forces of foreign countries engaging in activities for ensuring Japan’s peace and security.” Crucially, the legislation also changed the conditions in which Japan could employ “armed force” from exclusively defensive operations to “three conditions”: 1) a country or group attacks Japan or an attack against a country that “is in a close relationship with Japan occurs and as a result threatens Japan’s survival and poses a clear danger to fundamentally overturn people’s right to life, liberty, and pursuit of happiness;” 2) there are no other solutions to prevent an attack to secure Japan; and 3) if force is used, then it must be to “the minimum extent necessary.”
This change widens the scope of when Japan could use force to respond to a crisis. As tensions increase around the Senkaku/Diaoyutai Islands and within the Taiwan Strait, the JSDF’s ability to respond to a situation in a rapid fashion is critical. Although it remains unclear if Japan would respond directly to a crisis in the Taiwan Strait, the adjusted wording regarding the use of force gives it more flexibility than before. Considering the increasingly interconnected relationships between the United States and its partners, Taiwan is bound to fit into the category of a country with a close connection to Japan.
Another part of the developing defense architecture includes investments into the “multi-domain defense force” concept—Japan’s vision of joint operations, with a focus on cyber, space, and the electromagnetic spectrum. A part of this is the interconnectivity of Japan’s command, control, communications, computers, intelligence, surveillance, and reconnaissance (C4ISR) between all of its branches and allies. To this end, Japan plans to inaugurate a new digital agency next year as a part of its efforts to modernize and centralize its cyber defense capabilities. Moreover, its Ministry of Defense also put forth another record-setting defense budget in 2020, which included requests for new stand-off capabilities, research and development for its next-generation stealth fighter program, and even a hypersonic weapons development program.
The US-Japan alliance, the second pillar, is equally critical to both partners. More than 60 years following the signing of the US-Japan Security Treaty, the alliance continues to deepen cooperation in multiple domains to ensure the regional status quo. The alliance undertakes annual bilateral and multilateral military exercises to improve coordination between each country’s joint forces. Still, there is more the alliance can do to increase its coordination, especially on the defense front. Japan and the United States currently lack a truly functional joint defense planning group, which would allow both parties to organize and synchronize strategies based on crisis scenarios such as an attack on Taiwan.  As tensions increase in the region, both parties must develop the platforms necessary to effectively communicate during high-stakes scenarios.
The third pillar is security cooperation, a key focus for Japan. Given the size and complexity of the region, upholding the stability of the Indo-Pacific will require more than just one country’s contributions. On September 9, 2020, Japan and India agreed to a deal allowing both sides to “exchange supplies and services on a reciprocal basis during exercise.” This deal was a change of pace for India, which generally approaches its security unilaterally. Similarly, on November 17, 2020, Japan and Australia brokered an agreement enabling the two parties to reciprocally base their forces and undergo joint operations training. Both these deals and other developments point to Japan’s positive trend of deepening its role regionally.
Japan-Taiwan Security Relationship
Japan and Taiwan’s relationship, specifically as it relates to defense cooperation, is minimal. Still, that should not discredit recent developments. One program that serves as a testament to increasing relations is the Global Cooperation and Training Framework (GCTF, 全球合作暨訓練架構) launched by the United States and Taiwan in 2015, which Japan joined and has co-hosted since 2019. The GCTF gives Taiwan a space to share information related to health, cybersecurity, and many other topics with leaders from multiple countries. The 2020 workshop, focused on “Combating COVID-19 Disinformation,” hosted Japan-Taiwan Exchange Association Taipei Office Chief Representative Hiroyasu Izumi and AIT Director William Brent Christensen, as well as a number of cabinet-level leaders from the three countries. Although the GCTF does not include a defense component, creating a forum in which Japan and Taiwan can communicate is critical to developing a robust relationship.
Leaders from both countries have also made clear unofficially they want more robust ties. During former Taiwan President Lee Teng-hui’s (李登輝) memorial service in 2020, former Japanese Prime Minister Mori Yoshiro was in attendance and made headlines later for stating that a call between President Tsai Ing-wen (蔡英文) and new Prime Minister Yoshihide Suga was possible. Although it is unclear if the call took place, such an event would be unprecedented, as the leaders of Taiwan and Japan have not publicly spoken since 1972. Moreover, in its recent diplomatic bluebook, Japan described Taiwan as an “extremely important partner” and highlighted its attempts to involve Taipei within international organizations such as the World Health Organization (WHO).
Despite their limited engagement, Japan and Taiwan are geopolitically interlinked. Should a crisis occur within the Taiwan Strait, it would send the entire region into flux. If China were to conduct a military operation against Taiwan, the likelihood of missile strikes against Japanese-American bases in Japan to deny them access to a conflict would certainly be high. Although Japan and Taiwan’s current relationship is limited, it behooves the two partners to engage early and coordinate militarily when possible. If the United States’ engagement with Taiwan in 2020 serves as a harbinger of things to come, then increased cooperation is likely. Japan, Taiwan, and the United States should all take proactive steps to build out their relationship.
Building the Bridge
Based on China’s increasingly aggressive actions and assertive posture, it is clear that the United States, Japan, and Taiwan must collaborate on new ways to engage each other. Leaders from these countries should consider implementing the following policies to bridge the current gap:
- Develop a US-Japan Joint Defense Planning group to outline, prepare, and further integrate forces in case of a Taiwan Strait contingency. Given the increase of Chinese military exercises in the surrounding region and Beijing’s growing investment in high-end military capabilities, it is clear that the US-Japan relationship must take another step forward to integrate forces and plans.  This group should begin as a collaborative project to jointly develop a working understanding of how both parties could respond to various Taiwan Strait contingencies. Although the likelihood of an imminent conflict is low, preparing for the unlikely is critical. Later, this group could develop into the long-awaited US-Japan joint task force. Interoperability of joint forces is possible, but concrete action and training are needed. Considering the worries of a fait accompli over Taiwan and the Senkaku/Diaoyutai Islands, working from the same playbook is critical.
- Open official and unofficial crisis planning discussions between relevant flag officers from the United States, Japan, and Taiwan. There is much to be desired in the future relationship between the US-Japan alliance and Taiwan. A solid start would involve connecting the militaries of each party and exchanging ideas on planning scenarios surrounding a Taiwan Strait crisis. Publicly announcing crisis planning operations would also signal to China that all parties are interested in maintaining peace and stability in the region.
- Develop maritime and air intelligence-sharing platforms between Japan and Taiwan. This effort could include the United States as a broker; however, developing the bilateral relationship is critical. Considering the ongoing harassment by the PLA via Air Defense Identification Zone (ADIZ) and maritime incursions, both parties would benefit from sharing intelligence information to track patterns of where and when China conducts operations.
Japan has made it clear that it takes China’s rise seriously by undergoing significant changes to its national security infrastructure. While individual investments are important, cooperation between Japan and Taiwan is critical for the future stability of the Indo-Pacific. The relationship is currently minimal, but it should not stay that way for long, as balancing against China’s assertiveness will require a common strategy.
The main point: Japan is strengthening the core pillars of its defense infrastructure in reaction to China’s assertive behavior within the Indo-Pacific. Even though the United States is increasing its engagement with Taiwan, Japan lacks the same robust security partnership. In response, Japan (and the United States) should build out new avenues for defense cooperation to increase readiness in the face of growing uncertainty in the Taiwan Strait.
 John P. Niemeyer, “U.S.-Japan Coordination in an East China Sea Crisis,” Asia Policy 15, no. 3 (July 2020): 31–42.
 Tetsuo Kotani, “China’s Military and Paramilitary Activities in the East China Sea: Trends and Assessments for the U.S.-Japan Alliance,” Asia Policy 15, no. 3 (July 2020): 7–17.