Visit the Belmont Club and The Adventures of Chester for their excellent coverage of the unfolding events in Fallujah.
Military Operations in Urban Terrain (MOUT) are among the most difficult things undertaken by armed forces and traditional techniques have often resulted in exceptionally messy situations such as Stalingrad. The problems being encountered by the defenders of Fallujah are those of a force ill-equipped to deal with the modern world represented by the Marine and Army forces they are opposing. It seems to me the communications systems being employed by the US military allows movement to contact with less risk of accidental blue on blue engagement than in any other urban battle. By using overwhelming force, there is little chance of the opposing force being able to concentrate sufficient personnel to drive any wedges into the advancing coalition forces.
One of the advantages of exposure to joint commands I got to visit over my Naval Reserve career was an increasing awareness of how well our Army and Marines do their jobs. These guys are really, really good. In addition, they are really, really smart and professional. God bless them all.