Recently, I published the policy proposal “Democratic and Digitally-Driven Counterintelligence Enhancement: JEEADiS Policy Proposal“. Taking this opportunity, I would like to clarify the issue of a Taiwan contingency from the perspectives of international politics, international law, and security.

From China’s standpoint, any intervention by other countries in the sovereignty issue regarding China and Taiwan is asserted to constitute interference in internal affairs. Under international law, the positioning is that “China asserts this, but it remains an unresolved issue internationally,” and it can be organized as follows:

• There is no internationally agreed conclusion regarding the sovereignty of Taiwan.
• The United Nations General Assembly recognizes the People’s Republic of China as the representative of China.
• Taiwan’s non-membership in the United Nations does not mean that Taiwan is legally determined to be part of China under international law.

On the other hand, the issue of a Taiwan contingency is related to the discussion of a “situation threatening Japan’s survival” (存立危機事態), which appeared in Prime Minister Takaichi’s remarks, so it is a separate matter from interference in internal affairs.

This situation threatening Japan’s survival is defined in the following law premised on the Japan-U.S. Security Treaty, and formally refers to “a situation in which an armed attack against a foreign country that is in a close relationship with Japan occurs and as a result threatens Japan’s survival and poses a clear danger of fundamentally overturning the lives, liberty, and pursuit of happiness of the Japanese people” (Article 2 of the Act on Response to Contingencies Involving Armed Attacks, etc.).

In addition to “situations threatening Japan’s survival,” there are also “armed attack situations” and “predicted armed attack situations.” The “foreign country that is in a close relationship with Japan” of course refers to the United States, not Taiwan.

Act on Ensuring the Peace, Independence, and Security of Japan and Its People in Situations Involving Armed Attacks and Situations Threatening Japan’s Survival

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From China’s perspective, a Taiwan contingency is an internal affair, so the possibility of it becoming an “armed attack situation (direct armed attack by China on Japan)” is low, and Japan would basically not intervene.

However, if it leads to a “predicted armed attack situation” or “situation threatening Japan’s survival” due to attacks on U.S. forces, disruption of sea lanes, or spillover risks to U.S. bases in Japan, there is a possibility of taking specific measures prescribed by law (such as support for U.S. forces). The remarks by Prime Minister Takaichi, which drew significant attention and criticism from China, explained the above.

Now, regarding the United States: In recent years, the U.S. position has been consistent, officially maintaining “strategic ambiguity” while, under the Biden administration, explicitly stating multiple times an “intent to defend Taiwan.” Although this tendency slightly weakened during the Trump administration, the basic posture and position have not changed. (Note: As of December 2025, in Trump’s second term, the U.S. has returned to a clearer strategic ambiguity, with no major shifts in fundamental policy.)

The U.S. stance of “not denying military involvement and repeatedly demonstrating strong deterrence intent” is evident from the fact that, although there are no U.S. military bases in Taiwan, it actively engages in security around Taiwan through military training support to Taiwan and utilization of bases in allied countries (Japan and the Philippines), functioning as a deterrent against China.

This means that the United States views a Taiwan contingency as an issue for its own national security. The U.S. conducting interference in internal affairs or influence operations against other countries is not limited to Taiwan. At the root lies a distinctive view of sovereignty and strategic culture, in which the United States has historically prioritized its own security judgments over other states’ sovereignty claims. It is important to understand this U.S. view of sovereignty and strategic culture when considering Japan’s national security.