U.S. Defense Secretary Robert Gates' telling The New York Times what he learned under Presidents George W. Bush and Barack Obama goes beyond satire: "I will always be an advocate in terms of wars of necessity. I am just much more cautious on wars of choice."
Gosh, Bob, does that mean you wouldn't invade Iraq next time?
Afghanistan, by contrast, was a "war of necessity" in Gates' terms: official Washington believed that further bad things like 9/11 might happen to the United States if U.S. troops didn't go to Afghanistan to root out the al-Qaida terrorists (mostly Arabs) who had been given bases there by the country's Taliban leadership. It wasn't a very subtle strategy, but it was certainly driven by perceived U.S. national interest.