Taipei emptied streets and sounded air-raid sirens across the island Friday, running its annual Wanan civil defense exercise alongside live invasion-response drills that simulated a PLA landing. The Ministry of National Defense, under Wellington Koo since 2024, timed the exercise to coincide with the sharpest week of Middle East escalation in months: Iran's forces moved on the Strait of Hormuz, the United Arab Emirates said Friday its state oil tankers took drone fire transiting the strait, and Washington ordered a second carrier group into the region. Beijing's Taiwan Affairs Office did not need to fly a single additional sortie to make its point. The point made itself: the United States has one Navy, and this week it is spoken for.

That is the arithmetic Taipei is drilling against, not a hypothetical. A carrier ordered to the Gulf is a carrier not staged in the Western Pacific, and Washington has not named what force posture it would hold in reserve for a Taiwan contingency arriving in the same month as an Iran contingency. Koo's ministry has run Wanan every year since the 1970s; what changed this year is the audience. The drill was scheduled before the Hormuz attacks, and Beijing now watches Taipei rehearse an invasion response while Washington's second carrier steams toward the Gulf instead of the Taiwan Strait. Track whether the carrier ordered to Hormuz this week returns to the Indo-Pacific before October, when Taiwan's next reservist call-up cycle begins.