MSNBC's Michael Moran sums up the situation in Fallujah perfectly over at Hardblogger:

A week ago, it all sounded too good to be true: the murderous insurgents of Iraq, fearful of losing their base at Fallujah, were digging in by the thousands for a great confrontation with American troops and their Iraqi allies. But as American forces move in, it quickly became clear that most of the insurgents U.S. commanders were hunting had fled.

This has kept the intensity of the fighting -- and the casualties it generates -- down a bit, it is deeply disappointing to the United States. Rather than fight and die for Fallujah, the insurgency and its leadership have done what smart guerrillas have done throughout history when confronted by a more powerful adversary: they faded away and will fight and kill and maim another day.

I spoke with David Phillips, who spent the past four years as a senior advisor to the Bush administration on Iraq, about this for my Brave New World column this week. He says military officers never really bought the idea that the insurgents would stand and fight. "Why would they?" he asks.

Fallujah, he says, never was going to be the milestone the administration has built it up to be. "The insurgency is not in Fallujah, it is all over Iraq." [emphasis added]

Perhaps if the administration had not waited until after the election to launch the attack but rather did what it needed to do when it needed to do it, we could have knocked out a large portion of the insurgency. Instead, the insurgents are now across the entire country and there isn't yet much to do to stop them.