You spelled it out correctly RL. Those of us who oppsed this war to begin with knew it would go like this. So now we have a Shiite and Sunni "insurgency".....people who love their country and want to protect it........from us. And Bush won't back down. His "Bring 'em on!" rhetoric only inflamed them. Like one bully jumping on a smaller bully in a playground (when it's not even your playground), and then taunting the others.
You have a free-for-all.

Not to mention the baaad behaviour of certain troops in "interogating" the "enemy".
Hatred breeeds hatred.
Violence begets violence.

Bush went into this war with false premises. Far from staying the course to get Bin Laden and Al Queda in Afganistan, he jumped into democracy and visions of mass WMD for a country that was no viable threat to us or the world. And now we're paying for it.....through the teeth.

A quagmire, you say??
No, it's worse than that. It promises to be an untenable situation with endless deaths if a WAY OUT is not discussed with their leaders.
You see, we cannot remove the forces which controlled those forces through forces of our own. It is impossible. They are fierce and it is THEIR land, THEIR country. And now the Republican Guard is in charge of a couple of cities, and we can't break that?
My, my, better let them have it, you say?

Terrorism has been reproduced one hundred or one thousand times what it has been. Why, bring 'em on, Georgie!