As usual Mark Steyn has a brilliant column that further illustrates fallacy of the "get out now" crowd.
In war, there are usually only two exit strategies: victory or defeat. The latter's easier. Just say, whoa, we're the world's pre-eminent power but we can't handle an unprecedently low level of casualties, so if you don't mind we'd just as soon get off at the next stop.
Demonstrating the will to lose as clearly as America did in Vietnam wasn't such a smart move, but since the media can't seem to get beyond this ancient jungle war it may be worth underlining the principal difference: Osama is not Ho Chi Minh, and al-Qa'eda are not the Viet Cong. If you exit, they'll follow. And Americans will die - in foreign embassies, barracks, warships, as they did through the Nineties, and eventually on the streets of US cities, too.