No doubt there's value in holding cities. But the key isn't can you take over the city -- the key is how long can you hold it. If recent history is any indication - it won't be for long.
You may recognize William Lind as the guy that first expounded 4gw:
http://www.military.com/...,Lind_102104,00.html Unfortunately, our leaders do not understand the Fourth Generation, so it appears we are about to throw this opportunity away. We continue to bomb and shell Fallujah, which pushes our enemies toward each other. We seem to be readying an all-out assault on the city, which will have the usual result when Goliath defeats David: a moral defeat for Goliath. Many Iraqis will die, the city will be wrecked (as always, we will promise to rebuild it but not do so), and any losses the insurgents suffer will be made up many times over by a flood of new recruits. Never was it more truly said that, "We have met the enemy, and he is us."