. . . The violent encounter in a faraway land opened a two-year affair that would pit a Pentagon hierarchy wedded to longstanding rules of combat and discipline against a commander in chief with no experience in uniform but a finely honed sense of grievance against authority. The highest ranks in the Navy insisted Chief Gallagher be held accountable. Mr. Trump overruled the chain of command and the secretary of the Navy was fired. The case of the president and a commando accused of war crimes offers a lesson in how Mr. Trump presides over the armed forces three years...