You are blurring the difference between insurgent groups, who are Iraqi, by the way, and radicals committing terrorist acts and atrocities on hostages, some of whom are also Iraqi.   The Shi'a minority want to retain power in Iraq.  The US invasion of Iraq has led to an insurgency (which is really a Civil War in faint disguise), with the Sunni hoping ultimately to take control of the country.  The US wants the Shi'a to remain in power, because they will be an easier puppet to manipulate, so as it now stands the largely Sunni comprised insurgents will continue to fight US soldiers, and the battle is far from over.  Falluja is only the beginning.    Your notion that the insurgent groups are composed largely of terrorists is baseless.   Read about the history of Iraq and Iran, and you will see very clearly why this war is likely to continue.  I read a very good review article the other day on the history of turmoil in the region, and will post it as soon as I can find it again.   I think we will probably be fighting in Iraq a/o Iran for the next decade.

Gene

P.S. Woops, I got it reversed.   It's the Sunni minority in Iraq, and the group currently in power.   See post below.