I think you underestimate the US military a lot. The petrodollar or whatever is only powerful because the US is able to protect economic interests with its military power. Last I checked the next best countries are a decade or more and several hundred billion dollars behind. Although, a good argument can me made about internal fighting and political in-fighting and weak stomach of the US voter-base, which can be remedied with the next Iraq/vietnam.
Several parties playing a game. One plays chess, the other Go, and yet another checkers. Long term victory,Long term dominance and permanent superiority or win a lot of short term battles and exhaust your enemy. I don't know who will win but make no mistake this is a war, if not cold then maybe deep-frozen.