People's Republic of China — Japan and the Taiwan Strait

Summary

China and Japan hold one of the region's deepest economic relationships alongside a security relationship that has sharpened steadily, including disputes in the East China Sea that operate on their own logic rather than as a function of the Taiwan question. The two halves are not in tension so much as mutually enabling: the depth of the economic relationship is precisely what makes economic pressure a usable instrument between them, which is what was demonstrated after November 2025. This module records the interdependence because it is the standing condition, and records the coercion separately because it is an applied measure with a start date.

Why it matters

It is the constraint on Japan's Taiwan position that is not constitutional. Japanese governments weighing statements about a Taiwan contingency are weighing them against an economic relationship that Beijing has shown it will use, and the module's genuinely open question is whether that deters alignment or accelerates it.

What remains unknown

• This module does not record the date the modern economic relationship began. `validFrom` is given as 1972, the standard date for normalisation, and is context rather than a claim these sources establish.
• Vigil publishes no trade volumes, investment stocks or dependency ratios for either party. The interdependence is recorded as structural rather than measured, and no asymmetry is asserted.
• East China Sea disputes are noted as operating independently of Taiwan and are not covered by this module.