Historians attribute Hitler’s loss in World War II to many factors. The one most relevant to Trump is that many consider him to have been a megalomaniac who thought he knew better than his military experts.
How good was Hitler as a military commander? Was he, as his former subordinates claimed after World War Two ended, a meddlesome amateur who kept them from conducting the war properly? What were his strengths and weaknesses, his goals and methods? The answers to these questions reveal a man who was indeed responsible for Germany's downfall, though not entirely in the way that his generals claimed.
Hitler was, first and foremost, determined to command personally. According to his so-called Leader Principle (Führerprinzip), ultimate authority rested with him and extended downward. At each level, the superior was to give the orders, the subordinates to follow them to the letter. In practice the command relationships were more subtle and complex, especially at the lower levels, but Hitler did have the final say on any subject in which he took a direct interest, including the details of military operations, that is, the actual direction of armies in the field.
Moreover, as time went on he took over positions that gave him ever more direct control. From leader (Führer) of the German state in 1934, he went on to become commander-in-chief of the armed forces in 1938, then commander-in-chief of the army in 1941. Hitler wanted to be the Feldherr, the generalissimo, exercising direct control of the armies himself, in much the same sense that Wellington commanded at Waterloo, albeit at a distance. From Hitler's Leadership Style By Dr Geoffrey Megargee
So far Trump has only been at odds with the intelligence agency, not in major ways with the military that we know of. The comparison with Hitler and how he thought he knew better than his military did is reasonable because these are the two parts of government charged with national security.
Trump will be replacing one of the last three adults in the room, Dan Coats, with another totally unqualified sycophant Rep. John Ratcliffe:
Sen. Chris Murphy on Monday dismissed Rep. John Ratcliffe (R-Texas), President Donald Trump’s nominee to become the next director of national intelligence, as a “television character” who is an “inappropriate choice” for the historically nonpartisan post.
“I don't know this guy,” Murphy (D-Conn.) said on MSNBC. “I think he's a television character that the president has watched on TV, and he wants to put somebody in this position who's going to agree with his political take on intelligence.” Politico
Amazingly this leaves John Bolton as one of the two, along with Mike Pompeo, as the two high ranking officials who may tell tell the president he is wrong. One is John Effing Bolton! Who could have ever imagined being glad Bolton is the National Security Advisor.
Unless of course you count Ivanka.