Vice President Mike Pence announced a turning point in Washington’s relations with Beijing. In a speech Oct. 4 at the Hudson Institute, he acknowledged that four decades of attempts by the U.S. to make China a “stakeholder” in global norms and institutions had failed. The White House now promises to shift relations accordingly.

Mr. Pence didn’t offer specifics, but there’s no shortage of steps the administration could take to assert U.S. interests against China’s hegemonic goals. It should recommit to defending American allies...