US military planners are discovering that slums are the new centres of resistance.
The young American Marine is exultant. 'It's a sniper's dream,' he tells a Los Angeles Times reporter on the outskirts of Fallujah. 'You can go anywhere and there are so many ways to fire at the enemy without him knowing where you are.
'Sometimes a guy will go down, and I'll let him scream a bit to destroy the morale of his buddies. Then I'll use a second shot.
'To take a bad guy out', he explains, is an incomparable 'adrenaline rush'. He brags of having '24 confirmed kills' in the initial phase of the brutal US onslaught against the rebel city of 300,000 people.