MacArthur did not believe he was merely a general. He believed he was a historical force, like Caesar or Napoleon. This immense ego was both his superpower and his kryptonite.
He understood the power of image. The corncob pipe, the sunglasses, the crushed operational cap. When he landed at Leyte, he made the photographers retake the shot multiple times until he looked sufficiently grim and heroic wading through the surf. He was the first general of the media age.
After ruling Japan as Supreme Commander for the Allied Powers (SCAP), he treated presidents like equals (or inferiors). He didn't salvage Japan; he rebuilt it in his own image, drafting a constitution that gave women the vote and dismantled the aristocracy. He was a liberal reformer disguised as a conservative autocrat.
In Korea, his belief in his own infallibility finally broke him. He ignored intelligence that China was entering the war. He publicly threatened China with nuclear weapons, contradicting President Truman.
TELEGRAM FROM PRESIDENT TRUMAN (1951)
"I deeply regret that it becomes my duty as President and Commander in Chief of the United States Armed Forces to replace you as Supreme Commander..."
He came home to the largest ticker-tape parade in history, but his career was over. The lesson: Strategy without politics is just violence. Even Caesar must answer to the Senate.