An attack on the military would make a lot of sense. Trump needs to manufacture consent within the military before he can reliably use them to eliminate protests. So this ticks all the boxes. Can’t be small scale though. You need a significant death toll, you need spectacle, horror and shock. Needs to be a military installation in a highly visible location. You have to put on a show. Still wouldn’t significantly reduce the US’s military capacity, and you can bet it’s a sacrifice Trump is willing to make. Especially after that disappointing birthday parade.