Starship Trooper, Ender’s Game, and Dorsai!.
Someone else can pick the order, although given current events, I am leaning towards Troopers. google “The Battle of Athens” for historical precedent.
I’ve always loved Starship Troopers (the novel, not that wretched movie), and remember enjoying Dorsai!, but I must admit I’ve never gotten around to reading Ender’s Game. I’m told it is quite good.
My personal favorites on the list are (in no particular order): Neuromancer, A Canticle for Leibowitz, and the Elric saga.