China’s recent interference with ship-data broadcasts might provide a clue to Chinese military strategy, and give a preview of the opening moments of a future attack on Taiwan. In late October, international ship tracking services noticed a sudden decrease in ship data from Chinese ground stations. These land-based stations receive the Automatic Identification System (AIS) data that nearby ships broadcast. The stations normally relay this information, including the ship’s name, speed, weight, origin, and destination, to tracking services like MarineTraffic or VesselFinder. Although the ships (including Chinese ships) continued to broadcast their AIS data, Chinese land stations stopped forwarding that data. This interruption was very unusual, since AIS is a global system that provides real-time data on ship movements to prevent collisions, aid in search-and-rescue, and help with port planning. The International Maritime Organization requires AIS data broadcasting by all ships over 300 tons, and all passenger ships regardless of …