The desert is the 2nd best surface on the planet Earth for the U.S. military to engage in battle on. The desert has been called a quartermaster’s nightmare and a tactician’s dream. This is because in order to support any sizable force in the desert requires heavy mechanization. The desert is hard on equipment. However, no features can block movement or line of sight. Mobile forces are free to maneuver at will. The differences between heat and cold allow thermal imaging and other ‘high tech’ devices an ideal environment to work in. There are very few (If any) places to hide and slip away, avoiding death or capture. A human being can survive for something like 30 days without eating. A human can only last up to 3-4 days without water. If the United States must fight a war, Iraq is one of the best places on Earth for us. This is why the war has moved into the cities. This is the opposite from Vietnam because we controlled the towns and cities where the VC and NVA controlled and contested the countryside. The ‘surge’ plays well in this environment.
The U.S. and Iraq can interdict reinforcement and resupply in the cities. Once the army redeployed in Baghdad, each small chunk of the city could be isolated and cut off. Tactically you would be winning. They can’t fight it out in such small battlefields where they can be cut off so easily. Strategically, Iraq has been able to seize all of the major cities. Greater amounts of combat favor the conventional side in irregular warfare. With greater resources, more manpower and superior firepower, additional combat is generally on the side of the conventional forces. Toss in how we can isolate each individual battlefield and you have much of the reason why we are being successful in Iraq today.