Just another comment on urban warfare. I assume you have seen the American Civil War photographs of what used to be Atlanta, Columbia, Richmond, Petersburg, and Vicksburg. They are not pretty. In fact, those cities were all pretty much destroyed. Should you want to take a look, try Google images. I guarantee you there are lots of Civil War photos there.
Now, the American Civil War is often considered to be the first modern war, the first total war ever, in which the complete economic resources of both sides were thrown against one another, in which the static front became more important than warfare of movement, in which an entrenched defense was first seen to be stronger than the attack, in which primitive blitzkrieg (Sherman's march) was first used to outmaneuver a static defense, in which railroads and steamboats were first used for rapid troop movement and supply, in which there was mass conscription on both sides, in which new technology, especially the rifled musket with the conical bullet, was used for the first time. If they'd had machine-guns and barbed wire (both were invented within fifteen years after the end of the war) we'd have killed five million of each other. Actually, some 620,000 were killed in combat, and some two million total died from starvation, disease, and the like. The wounds the Civil War inflicted upon American society aren't completely healed yet.
I would suggest that future Saddam Husseins and Osama Bin Ladens should devote some serious study to the American Civil War and think, "If they were willing to do that to one another, what might they be willing to do to us?"