Military parades with lots of hardware appeal to countries that have something to prove. For Israel in the 1950’s and 1960’s, it was that the tiny state had the muscle to survive; for France in the late 19th and 20th centuries that defeat and ruinous victory had not dimmed her martial prowess; for the first three presidents of the Cold War that the United States was the same country that had won World War II and could triumph in an entirely novel global contest against an opponent with weapons that could obliterate cities at a stroke.
Parades are also a way of paying tribute to the troops. The troops of the past, however, were citizen soldiers in the old sense: temporarily uniformed men (and later, women) who had answered their country’s call. As war has become for the vast majority of Americans a spectator sport, the problem becomes why, how, and to what extent public thanks is due. At one extreme there is the sentiment—darkly put out by John Kelly on a number of occasions, and most recently in his October 17, 2017, news conference about fallen soldiers—that civilians can not only never be grateful enough, but rather, must accept a position of permanent moral inferiority to those who serve.
That kind of parade becomes an act of moral extortion, a false claim to a monopoly of courage and civic virtue.