I have the utmost respect for all our soldiers, however, I still reserve the right to think that the entire situation in the Middle East is for naught. Unfortunately, we can't stay forever, and as soon as we leave, no matter how we leave it, they will devolve into a civil war between the shia and sunni factions. The government will crumble and many people are going to die.
I don't believe for a second that it will become any more terrorist haven than it currently is, after all, the shiites will likely control Iraq and, unless the Middle East experts are complete idiots, the shiites hate al queda. More likely they will drive al queda fighters out of the country, or kill them outright.
Conclusion is that the conclusion is fore gone...the only thing the US has any control over is when it happens.