All Iraq did was give radicals an excuse to be radical. It's like stirring up you soup. The stuff rises to the top. Those that were created because of a love affair with Saddam Hussein can die along with those who actually thought Osama Bin Laden was a hero in the first place.
And there's no propaganda they can use other than to show how depraved Muslims act without a dictator. The fact that we introduced a Democratic system and gave them the freedom to vote is not something Al-Queda can paint as evil. I don't think that was their plan. Their plan actually backfired. Our response did not erupt the region into Islamic praise and defense. One would have to acknowledge that they were defending Saddam Hussein's regime in order to tie it into Islam. And nobody cared enough to flock to Afghanistan to defend the Tali-Ban. Even other radical organizations distanced themselves from Al-Queda because they knew on 9/12 that they went too far. Chants of "Democracy" is what Osama Bin Laden died hearing. That and his name (apparently).