Japan's PM Takaichi says country's military could step in if China moves on Taiwan

Japan's new Prime Minister Sanae Takaichi sparked a diplomatic uproar after stating that China's use of force against Taiwan could cause Japan to exercise its right of collective self-defense.

During Japan's Lower House Budget Committee session on Nov. 7, Takaichi stated that if China were to take military action against Taiwan, such as using warships to impose a blockade, Japan could likely consider it a "situation threatening Japan's survival." In such a case, Japan could, under its legal framework, deploy its military, the Self-Defense Forces (SDF), to exercise the right of collective self-defense.

China sees self-ruled Taiwan (officially the Republic of China) as a breakaway province and has not ruled out the use of force to annex the island.



Dr. Wang Hung-jen (王宏仁), a Professor in the Department of Political Science at Taiwan's National Cheng Kung University and Chairman of the Taiwan Society of Japan Studies, told TCN that Takaichi's use of terms such as "warships", "blockade," and "use of force" indicates that once a situation threatens Japan's lifeline through military means, the Japanese government would no longer limit its response to diplomatic statements or economic sanctions, but could instead invoke the right of self-defense within its legal framework.

Wang noted that such remarks reflect not only Takaichi's individual strategic judgment but also serve as a microcosm of Japan's broader political climate and growing sense of security anxiety.

Professor Ho Szu-shen (何思慎) of the Department of Japanese Language and Culture at Fu Jen Catholic University told TCN that Japan has never claimed it would defend Taiwan, nor is it capable of doing so. "Japan is merely conducting contingency scenarios," he added.

Ho said, "When a neighbor's house catches fire and the flames spread to your own, you have to consider how to respond."

Ho stated that Takaichi's comments do not constitute a security commitment to Taiwan, but rather address how Japan should respond if a Taiwan contingency spills over to affect Japan directly.

Reflecting on how the US might react to a contingency involving Japan, Ho said, “The United States and Japan are allies, and while the US has an obligation to defend Japan, it will act with caution and will not allow itself to be drawn into a war that it does not wish to participate in. This is especially true if the conflict involves China, in which case the US would be even more cautious.”

Xue Jian

China’s Consul General in Osaka, Xue Jian (薛劍), responded to Takaichi's remarks with a post on X that read, “Filthy heads that brazenly barge in should be cut off without hesitation. Are you prepared for that?” The post was no longer viewable on the evening of Nov. 9.

Xue's comment drew criticism from political parties across Japan’s spectrum, who called on the Japanese government to declare him persona non grata. Japan has lodged a formal protest with Beijing over the remarks.

On Nov. 10, Takaichi once again expressed her views on the Taiwan Strait issue during a session of Japan’s National Diet. She said that her remarks reflected the Japanese government’s conventional position and declined to withdraw them.

On Nov. 11, Japan's Chief Cabinet Secretary Minoru Kihara confirmed that China had lodged a protest against Prime Minister Takaichi’s earlier remarks suggesting that Japan might use force alongside the US in the event of a Taiwan contingency. Kihara added that the Japanese government had explained to Beijing the underlying intent of Takaichi’s statements and Tokyo’s official position.

"Japan would never make a formal security commitment to Taiwan"

Professor Ho said that Takaichi's remarks have not gone beyond the existing legal and diplomatic framework traditionally held by the Japanese government on the Taiwan issue. Ho said that Japan would never make any form of security guarantee or commitment to Taiwan, since doing so would destroy Japan-China relations, something Ho described as "not even worth imagining." Japan still needs to maintain a functional and interactive relationship with China in its diplomacy, he added.

Ho said that Taiwan hopes the US and Japan will pay close attention to the Taiwan Strait. When the US and Japan hold bilateral talks, they often express the desire for peace and stability in the Strait, he added.

Both countries must maintain at least a level of dialogue with China so that they can address the Taiwan Strait issue through diplomatic means, he said.

More pragmatic and hardline policies

Professor Wang stated that Prime Minister Takaichi's stance is more pragmatic and hardline compared to that of Japan's former Prime Minister Shinzo Abe.

Wang said that Abe used the phrase "A Taiwan emergency is a Japan emergency" to construct a strategic concept, but maintained a considerable degree of ambiguity during his tenure. In contrast, Prime Minister Takaichi has transformed that rhetoric into a concrete policy tool, clearly outlining how Japan would respond to a potential Taiwan Strait contingency through its legal framework, Wang added.

Wang noted that under Prime Minister Takaichi's leadership, Japan's foreign behavior and policy language may evolve into a new strategic direction, in which the country's legal framework provides legitimacy for potential military action, diplomatic statements are clarified to explicitly safeguard Japan's national interests, and limited-scale military exercises are conducted to test Beijing's reactions.



The future of Taiwan-Japan relations

Professor Ho stated that Taiwan should avoid overinterpreting or overimagining Takaichi's remarks as signaling any breakthrough in bilateral relations. Ho said the security environment surrounding Taiwan directly affects Japan's southern security, and that successive Japanese prime ministers have consistently prioritized Japan's southern security concerns, a long-standing policy stance, he added.

Ho said that if Taiwan-Japan relations are to achieve a genuine breakthrough, more practical measures would be necessary. These include Japan's support for Taiwan's accession to the CPTPP, or progress in the long-discussed but so far unrealized Economic Partnership Agreement (EPA) between the two sides, he added.

Professor Wang said that Taiwan-Japan relations may continue to deepen institutionally and symbolically. He pointed to several developments, including the brief meeting between Prime Minister Takaichi and Taiwan's APEC representative Lin Hsin-i (林信義) in late October, the visit to Taiwan by the Japan‑ROC Diet Members' Consultative Council to attend National Day celebrations, and the Taiwan‑Japan Exchange Summit held in early November, which adopted the Kanagawa Declaration.

He said that Prime Minister Takaichi's approach reflects her political ambition as Japan's first female prime minister.

Wang explained, "Takaichi understands that in an era of intensifying US-China rivalry and rising uncertainty in the Taiwan Strait, Japan can no longer maintain the same degree of strategic ambiguity as before. Through legal clarification and military preparedness, Takaichi is making Japan an increasingly indispensable and visible key participant in Taiwan Strait affairs."