美国表示已经在台湾驻军一年以上

WSJ原文

WASHINGTON—A U.S. special-operations unit and a contingent of Marines have been secretly operating in Taiwan to train military forces there, U.S. officials said, part of efforts to shore up the island’s defenses as concern regarding potential Chinese aggression mounts.

About two dozen members of U.S. special-operations and support troops are conducting training for small units of Taiwan’s ground forces, the officials said. The U.S. Marines are working with local maritime forces on small-boat training. The American forces have been operating in Taiwan for at least a year, the officials said.

这时候高调公开宣布（虽然早就知道了），应该就是测试底线。