The worry about Taiwan comes as China wields new strength from years of military buildup. It has become more aggressive with Taiwan and more assertive in sovereignty disputes in the South China Sea. Beijing also has become more confrontational with Washington; senior Chinese officials traded sharp and unusually public barbs with Secretary of State Antony Blinken in talks in Alaska last month.

A military move against Taiwan, however, would be a test of U.S. support for the island that Beijing views as a breakaway province. For the Biden administration, it could present the choice of abandoning a friendly, democratic entity or risking what could become an all-out war over a cause that is not on the radar of most Americans. The United States has long pledged to help Taiwan defend itself, but it has deliberately left unclear how far it would go in response to a Chinese attack…

U.S. officials have noted People’s Liberation Army actions that seem designed to rattle Taiwan. For example, Chinese aerial incursions, including flying around the island, are a near-daily occurrence, serving to advertise the threat, wear down Taiwanese pilots and aircraft and learn more about Taiwan’s capabilities.