Atrios asks:

I know this the standard line these days, as getting the Amurkan people behind spending $87 billion to help those poor Ay-rabs out for humanitarian reasons is damn near impossible, but do people really believe it? I know the conservative Borg will keep spouting it, but can they honestly believe that we are now in Iraq to fight terrorists?

Switch that wording around: "We are in Iraq now to fight terrorists", and you'll get the reasoning. Remember, the rationale doesn't have to be consistent (hence the switch from WMDs to humanitarianism) as long as it fits a plausible interpretation of the situation on the ground.

In other words, we're now enmeshed in full-bore mission creep. Yes, the Powell doctrine was specifically designed to prevent that. The Powell doctrine is dead.