You need to keep in mind, war unites people REALLY fast and easily, ESPECIALLY if it's a defensive war. Nothing unites people like The Other, The Foreigner, The Invader, The Occupier, attacked us, bombed our cities, killed our civilians, and occupied our homeland. The Jingoistic shit that came out of 9/11 and Pearl Harbour weren't exaggerated and aren't strictly American traits.
There will be a massive insurgent movement, that will make occupation a certainty, anyone who thinks there won't is lying to themselves.