For, say, 60 years. Make that one district a paradise. Call it the Free State of Edessa. It could be for the Army in Central Asia what Okinawa is for the Marines in the Pacific.
Granted, I put about 30 second of thought into that strategy. There are other legitimate strategies, like go in and go out every 5 years.
But, I was never under any illusions that this war was going to last less than 100 years. That's why the DOD started calling it the Long War early on...but the politicians decided that was a very bad name.