While folks can argue the costs all day long.
Where exactly are those funds going? Soldiers, US equipment MFGs like the indiana company that makes the Up-armor humvee, Kellog, Brown, Root(ack, Halliburton! heh), etc.
These folks act like this money has been tossed on a big pile and torched. It wasn't and I suspect much of it will and has come right back to the US.
As for the money coming right back to the USA.....the folks that so oppose haliburton would love to see all that money go to a french company instead. That way it wouldn't cycle here and would solve the french rioting problems by allowing it to cycle there instead
/sarcasm
/sorry, just couldn't resist ;-)