This doesn't mean that the McCain plan to send more troops to Iraq can't work -- but the last time we tried the more troops route, it led to this:
Missing from virtually all of the coverage of this proposal is a little thing called Operation Forward Together, which was launched during the summer of '06 in Baghdad. It's an odd omission, since Forward Together was pretty much exactly what the advocates of the "go big" strategy have in mind, and there are lessons in what happened. As part of the operation about 6,000 Iraqi security forces were sent to Baghdad, along with about 5,500 additional American troops, to try and tamp down the spiraling violence in that city.
But despite McCain, Lieberman and Kagan's conviction that more troops equals victory, Forward Together didn't work out so well. On October 20, the Washington Post reported that according to the Army itself, the tactic failed: "A two-month U.S.-Iraqi military operation to stem sectarian bloodshed and insurgent attacks in Baghdad has failed to reduce the violence, which has surged 22 percent in the capital in the last three weeks, much of it in areas where the military has focused its efforts ... The assessment by Army Maj. Gen. William B. Caldwell IV followed a 43 percent spike in attacks on U.S. and Iraqi forces in the capital since midsummer that has pushed U.S. military fatalities to their highest rates in more than a year."