Perhaps a major base in each major region of the country, away from populated areas. We could get it down to 3 or 4 large hubs easily. From there, we could provide the Iraqi military and police with all the air, intelligence, logistics, and training they'd ever need.
It's a win/win scenario for everyone. We'll stop taking casualties and the Iraqis will get their country back. The insurgents, on the other hand, will be stuck in rebellion against an Arab government, not a foriegn army.
If the United States Marine Corps can take an eighteen year old kid right out of Burger King, and within 16 weeks, train him to be a fighting machine, why can't we do it with the Iraqis after two years?
The answer is simple: The Iraqis lack the will to succeed. The insurgants can strike at will killing anyone they so choose. The Iraqis police and military are walking a fine line between the different sects and will fall on the side of the winner of the civil war that is sure to come.