The Taiwan Strait

The Taiwan Strait separates the Chinese mainland from Taiwan by between seventy and a hundred and twenty nautical miles. An unofficial median line ran down the middle for decades as a tacit boundary for military aircraft; since 2020 it has been crossed routinely, and the crossings themselves became the standard measure of tension.

The political dispute is about status. Beijing treats Taiwan as a province and does not renounce the use of force. Taipei governs itself with its own elections, currency and armed forces. Washington maintains formal relations with Beijing while supplying arms to Taipei under domestic law, and deliberately does not say whether it would intervene militarily - the policy known as strategic ambiguity.

For markets, the crucial point is that the range of possible events is very wide and very unevenly likely. Exercises, airspace incursions and cable cuts happen regularly. A quarantine or blockade would be an enormous escalation. An invasion is a different category again. Treating these as one risk produces prices that are wrong for all three.

Taiwan manufactures the overwhelming majority of the world's leading-edge logic chips, and a single company accounts for most of that. Nothing in the modern economy - phones, cars, servers, weapons, artificial intelligence - is built without them, and no alternative capacity of comparable capability exists anywhere else today.

The second exposure is shipping. A large share of the world's container fleet passes through or close to the strait each year, and it sits on the main routes between north Asian manufacturing and the rest of the world. Rerouting is possible around the east of Taiwan, but the additional distance and the insurance response would raise costs across Asian trade immediately.

The third is the supply chain around the chips: advanced packaging, testing and specialised components that are also concentrated on the island. This is the part most often missed - even a factory rebuilt elsewhere would still depend on steps that currently happen in one place.

Three legal and political instruments frame everything. The United States maintains unofficial relations under a 1979 domestic statute that commits it to providing defensive arms and to regarding coercion as a matter of grave concern, without promising intervention. Beijing's own 2005 legislation authorises non-peaceful means in defined circumstances. Neither document is ambiguous about intent; the ambiguity is entirely about response.

The calendar matters more than in most flashpoints. Taiwan holds presidential and legislative elections every four years, most recently in 2024, with the next in 2028; local elections fall in between. Chinese leadership meetings and party congresses set their own rhythm. Tension has historically risen around these dates rather than at random.

The observable record is unusually good. Taiwan's defence ministry publishes daily counts of aircraft and vessels detected around the island, including median line crossings. That published series is what a well-written market can settle on - it is dated, official and continuous.