China is pushing more coast guard and research ships into the waters east of Taiwan, and US analysts read it as preparation for a possible conflict — bad news for Taiwan and for US forces in the region.

• Taiwan's coast guard spotted a record 244 Chinese ships around the island in July, most of them coast guard vessels.
• The waters east of Taiwan matter most in a war: that is where submarines operate and where US and allied ships would approach from.
• The activity looks like data-gathering — mapping the sea floor and practicing missions far from China's own coast.
• China has also started what it calls "routine law enforcement patrols" east of Taiwan and ran a seafloor survey there in August.
• Taiwan cannot match China ship for ship, so the advice is to watch closely, lean on drones, and publicize Chinese movements fast.

Outlook: Expect the patrols to become permanent, with the US likely to share more sea intelligence with Taiwan, Japan and the Philippines.