They're still going to obey his orders. They're still going to go to the Ukraine and die fighting our distant cousins. Military has been purged over the last decade or two. Obama first, then Trump, then Biden- all possible dissenters are gone. Units are mixed up and moved around so that you have a majority of followers in any given unit; fewer "troublemakers" means lower chance of mutiny, higher chance of them being bullied by the brainwashed majority.