Catch a Tiger by the Tail
Kerry's got to figure out a way to coordinate his contradictory positions that the war was a mistake that he can win, and the best way for him to do that is to expand on the argument that he's been making that he will be a better commander in chief in the war on "terra", as everyone in the western world seems to pronounce it.
In enlarging on that claim, he needs to explain that terrorist proliferation is a manifold problem, with manifold entry points. Diving into the fight with Islamic extremists via Iraq was a huge blunder, but we've got the tiger by the tail now. He should invoke D-Day, which could have been a disaster.
Bush has a great line of attack with the patronizing admonitions against defaming our allies. Kerry could craft a devastating parry if he were to hail their support, while assailing the US plan of attack. But instead of implying that the only reason to stay in Iraq is to clean up the mess we've made, Kerry needs to make clear that Iraq was an obscure entrance into the haunted house which is Islamic extremism. We're stuck in the hall of mirrors now because we chose the wrong door: Iraq.