In his review of Cobra II, Andrew Bacevich encapsulates the inherent contradiction of the Iraq invasion as concisely as I’ve seen anywhere:
Rumsfeld’s grand plan to transform the US military was at odds with the administration’s grand plans to transform the broader Middle East. Imperial projects don’t prosper with small armies that leave quickly: they require large armies that stay.
For the succinctness to work, one needs a rudimentary understanding of the “grand plans” alluded to. The review provides that, if it is lacking.