President Donald Trump’s phone call with Russian President Vladimir Putin on Feb. 12 marked the beginning of the end of the three-year war in Ukraine. It also opened a new phase in America’s trans-Atlantic relations. We shall soon discover whether it also means the beginning of the end for NATO and the further destabilization of a Europe unwilling to defend itself, or a rebalancing in which a revitalized Europe buttresses the Trump administration’s global strategy. It is time, Trump announced on his Truth Social app after talking with Putin, to stop a “ridiculous” war that has caused “massive, and unnecessary, DEATH and DESTRUCTION.” The common response from the leaders of seven European states, including Britain, France, and Germany, seemed more interested in the process than the peace: “Ukraine and Europe must be part of any negotiations.”...