At 12:46 pm on January 20th Trump had the portrait of Mark Milley removed from the wall of the Pentagon. Biden pardoned Milley for good reason. Trump said he committed treason: In normal times, the chairman of the Joint Chiefs, the principal military adviser to the president, is supposed to focus his attention on America’s national-security challenges, and on the readiness and lethality of its armed forces. But the first 16 months of Milley’s term, a period that ended when Joe Biden succeeded Donald Trump as president, were not normal, because Trump was exceptionally unfit to serve. “For more than 200 years, the assumption in this country was that we would have a stable person as president,” one of Milley’s mentors, the retired three-star general James Dubik, told me. That this assumption did not hold true during the Trump administration presented a “unique challenge” for Milley, Dubik said. Milley was careful to refrain from commenting publicly on Trump’s cognitive unfitness and moral derangement. In interviews, he would say that it is not the place of the nation’s flag officers to discuss the performance of the nation’s civilian leaders. But his views emerged in a number of books published after Trump left office, written by authors who had spoken with Milley, and many other civilian and military officials, on background. In The Divider, Peter Baker and Susan Glasser write that Milley believed that Trump was “shameful,” and “complicit” in the January 6 attack. They also reported that Milley feared that Trump’s “ ‘Hitler-like’…