In a democracy, no one should be comforted to hear that generals have imposed discipline on an elected head of state. That was never supposed to happen in the United States. Now it has. Ultimate power to shape American foreign and security policy has fallen into the hands of three military men: General James Mattis, the secretary of defense; General John Kelly, President Trump's chief of staff; and General H.R. McMaster, the national security adviser. They do not put on their ribbons to review military parades or dispatch death squads to kill opponents, as members of old-style juntas did. Yet their emergence reflects a new stage in the erosion of our political norms and the militarization of our foreign policy. Already they have exerted a stabilizing influence. Mattis refuses to join the rush to bomb North Korea, Kelly has imposed a measure of order on the White House staff, and McMaster pointedly distanced himself from Trump's praise for white nationalists after the violence in Charlottesville. Being ruled by generals seems preferable to the alternative. It isn't. Trump has made clear that when he must make foreign policy choices, he will defer to my generals." Military commanders are trained to fight wars, not to decide whether fighting makes strategic sense. That is properly the job of diplomats. Many Americans ... are so disgusted by the corruption and shortsightedness of our political class that they turn to soldiers as an alternative. It is a dangerous temptation.