Yeah, we've had military parades before but mostly after military victories. Because Trump seems to be an autocrat-wannabe and also because he seeks to cut lots of useful stuff in the budget (like the Centers for Disease Control doing much work in the world to prevent epidemics from becoming pandemics--strange for a germophobe to do that), this expensive enterprise to make him feel good is being read as part of that larger destruction of democratic norms.
Which gets me to civil-military relations. An essential but mostly overlooked ingredient for democracy is civilian control of the military. This is always a difficult relationship since the two sides have very different perspectives and cultures and all the rest. The concern in much of the literature on it is whether the military will "shirk"--do more or less than it is supposed to do. For instance, a few months ago, it became known that the various branches of the armed forces were not informing the National Gun Registry folks about the domestic abuse and other crimes committed by soldiers, sailors, marines, airpeople. Much of the literature is focused on how the civilians can create structures and activities to make sure that the military folks do what they are supposed to do. Indeed, that is the heart of the Steve/Dave/Phil project that has taken me to Brazil, Japan and elsewhere.
What this literature only sometimes addresses is when the civilians are the ones deliberately screwing things up. We have much less civilian control of the military right now because Trump has delegated most of the decision-making to the folks in uniform and to a guy who was in uniform until just a few years ago. That was not good, but now we have the President seeking to have the military be more clearly part of the effort to prop up an unpopular government as he calls normal opposition to his regime "treason." This is all awful, and it is all dangerous.
Building norms and institutions takes generations, but destroying them does not. Trump is doing much damage to civil-military relations, making the crises under Obama or Bush or Clinton seem incredibly trivial. The next President and next SecDef will have to do much work to salvage the relationship between the civilians in charge and the military.
There is one hope, but, well, not much of one: Congress can refuse to authorize the money for this. But given how willing Paul Ryan, Mitch McConnell and majorities of Republicans in both houses are willing to sell out everything, I am not optimistic that Congress will play its role in American civil-military relations. As it turns out, the original driving force of the big project was my idealization of Congressional oversight that might be just as dead as the rest of American political norms.
Finally, the only military parade I want to see is this one: