Marilyn Hubalde still remembers the first time she heard the thunderous chop of military helicopters swooping over this northernmost outpost of the Philippines, about 145 kilometers from Taiwan. It was April 2023, when Filipino and American troops descended on the cluster of 10 emerald green islands of Batanes province for amphibious warfare drills.

"We were terrified,” the 65-year-old Hubalde recalled. "We thought China might attack when they learned there were military exercises in Batanes.” Hubalde’s helper, who was in the fields when the troops arrived, panicked and hid in the woods until nightfall. "She thought the war had already started,” said Hubalde, who owns a variety store in the provincial capital, Basco.

Since then, Batanes’ 20,000 residents have become accustomed to high-tempo war games in these islands of tightly packed towns and villages wedged between rugged slopes and stony beaches. Among them: a series of joint exercises from April to June this year in which U.S. forces twice airlifted anti-ship missile launchers here.