As for Europe -- I didn't say you control their economy, but US probably CAN ruin any european economy within days (this is already a form control). Then there's NATO. US dollar isn't worth a tenth of its current market value. Then, when US says that this country is bad and noone's to deal with it everyone else obeys even against their interests and sometimes -- against plain logic. Third world deals with dollars because if they don't there will be another 'peace keeping operation' in their region. And of course us dollar is the ONLY reserve world's currency and everyone's aware of that. Euro cannot compete with dollar, in fact Euro is probably even less stable to begin with. Federal Reserve prints green paper in trillions and exchanges them with something of real value (oil, gold, energy plants, real estate, etc). IN EXCHANGE OF GREEN PAPER!
Do you think the rest of the world is just so stupid that nobody sees that? Everybody knows, but who's going to argue with aircraft carriers and cruise missiles scattered all over the world?
About heroin - you can dig out the stats. During the period of American occupation the heroin production has QUADRUPLED there. Taliban used to burn the fields and was the only government there who managed to actually reduce it. (No, I'm not a Taliban sympathizer, but I don't flee from the facts). Americans have their faults but they were never known to give anything for free. It's against their nature. So when they say that the military's there to protect someone else's interests I laugh.
You say that the generals are not that smart, that's true for the most of them, but I doubt those who make real decisions are that stupid, and of course there're politicians around to order things around.