For a country that spends such vast sums on its national security apparatus—many times more than the enemies that supposedly threaten it do—the United States has a strangely invisible military establishment. Military bases tend to be located far from major population centers. The Air Force’s vast missile fields, for instance, are hidden away in the plains of the northern Midwest. It is rare to see service uniforms on the streets of major cities, even Washington. Donald Trump did dream of holding a “beautiful” military parade down Pennsylvania Avenue, complete with “a lot of planes going over and a lot…