Some things don't need to be book-length! Hamid is one of our most thoughtful and well-rounded thinkers, and he's at his best when he is forced to get across difficult ideas in a constrained space. While The Case for American Power is by no means gargantuan, the amount of philosophy and graduate-level political theory that Hamid stuffs in there dilutes the already nuanced perspective he's sharing.
The best moments here were when concrete differences were shown between how America uses, or doesn't use, it's power, and how China and Russia project their own version of power int he world. I wish there had been a bit more speculation on what a world in which Russia and/or China WERE the hegemonic power looked like. I got so excited when we got close to those extrapolations, and it always felt like I was being pulled back to Earth just when it was about to get truly interesting.