Petraeus Calls Iraq War ‘Exceedingly Complex’

The title of this thread which is the title of a NY Times article could be considered for the "no duh" moment of the year. From the initial planning stages of the war in Iraq it was known by some that this was going to be complex that the mere "shock and awe" was not going to be enough and that is where some of the groundwork for the failures began.

The real question continues to be despite the ‘Exceedingly Complex’ aspect, what can be done? It's been as much confirmed that the surge did not create the outcome the Bush administration wanted:

The general noted that the recent troop “surge” was meant to create some breathing room for Iraqis to move closer to political reconciliation. “It has not worked out as we had hoped,” General Petraeus wrote.

What possibly can be next? A bigger surge? Or a withdrawl?