America has always had differences with our allies, on matters both meaningful and trivial, but in the past, those differences were mainly over technicalities, margins, and details. Western institutions like NATO bring together nations who share a broad set of Western values that, to some, may seem quaint today: a robust defence of free markets, individual liberty, and human rights. We don’t have to agree on everything, because we agree on the fundamental things.No longer. NATO leaders may have had their doubts from time to time about American Presidents’ seriousness, intellectual heft, or domestic political strength. Until now, however, not one of them believed the American President actively sought favour and approval from the leader of totalitarian Russia. Until now, they never thought that an American President would put pleasing a Russian strongman over the values, peoples, and nations of the NATO alliance.