The U.S. Congress has seen the introduction of a remarkable 60 bills that relate to Taiwan this year, as Democrats and Republicans cross the aisle to support the island's continued survival amid increasing pressure from China.

American politics are often described as some of the most divisive among Western democracies, with lawmakers almost always voting along party lines. But beyond the domestic strife in both chambers, Taiwan appears to be a rare issue on which Congress can coalesce for bipartisan action.

Defense planners in Taipei and Washington have watched as the Taiwan Strait military balance has slowly slipped away...