Although Donald Trump has never been modest about his abilities or reluctant to exercise personal power, during his second term in office he has shown clear signs of megalomania. These signs include his blatant demands for the territory of other nations, his massive military buildup, his dispatch of U.S. military forces into combat, his disdain for the United Nations, and his establishment of a Trump-controlled "Board of Peace." This descent into megalomania is deeply disturbing, for the dangers to the world, and even to human survival, are sharply enhanced by one-man rule.