China has pushed a maritime militia vessel into waters east of Taiwan for the first time, a worrying sign that Beijing is widening the area where it tries to act like it is in charge.

• A Chinese fishing boat that doubles as a militia ship was spotted in August off Taiwan's east coast — the first time one has turned up in that area.
• Taiwan's defence ministry says China dresses up these intrusions as law enforcement or science research to stretch its reach without starting a fight.
• The aim is to build the false impression that these are Chinese-controlled waters, which directly challenges Taiwan's right to police its own sea.
• Taiwan's east coast matters because it faces the open Pacific and has long been the safer side, away from the Taiwan Strait.
• The military says it is tracking sea and air movements and will respond together with the coast guard.

Outlook: Expect more of these grey-zone probes around Taiwan, with Taipei leaning on its coast guard to push back without escalating.