Trump says he wants a massive military parade down Pennsylvania Avenue on July 4

Bad idea. Incredibly bad idea. Probably the worst idea that was ever conjured up in a free, democratic society.

Leave the Pomp & Circumstance stuff for the Parade Field.

The parade is not needed. In the immortal words from the Geto Boys "Damn it feels good to be a gangsta"
"But real gangsta-ass niggas don't flex nuts
'Cause real gangsta-ass niggas know they got 'em"

Leave the giant military parades for the "rocket man."

Well let's see-- flying our bombers over the Korean Peninsula and deploying the THAAD antimissile system there gave Kim a very upclose look at our military power and it hasn't had any effect on Kim's nuke and missile testing at all, unless to increase it. We've given Iran and terrorists up close looks at our capabilities for years with little effect. So a parade in Washington DC is supposed to impress any adversary and show them something they don't already know about our military?

Trump inquired about having military vehicles in his inaugural parade as well. This is all about his ego, nothing more. He wants to stand up there on the stand and strut like Mussolini because he wants to "out strongman" all the strongman leaders that he admires so much.

On a separate note, sometime in the late 80s or early 90s the Army put out a policy telling post commanders to minimize Independence Day parades that tied up the troops and screwed them out of celebrating a holiday that is very important to many of them. Getting a couple of comp time days the next week (if you were lucky) didn't cut it. So there is no need to screw all those troops, much less waste the gazillion mandays that would go into washing and repainting the vehicles a dozen times and marching rehearsals that would inevitably accompany such a display. It would end up being a very long run for a very short slide.