President Trump has made no secret of his disdain for our NATO allies. In the past month or so, he has called them “cowards” and NATO a “paper tiger.” But, as I have written elsewhere, his notion that we should just get out of NATO is blocked by both the NATO Treaty and by a specific U.S. law that requires either a resolution passed by both houses of Congress or a two-thirds vote of the Senate. Neither is going to happen.

Mr. Trump, as commander-in-chief, has constitutional authority to remove troops from the nations that have refused us the use of our bases to attack Iran. The United Kingdom, France, Spain, Italy, and Germany have all refused use of our bases there or use of their airspace or both. …