With U.S., British, and Iraqi forces now inside Falluja, it's worth considering what the U.S. Army says about military operations on urbanized terrain (MOUT). This is from Army Field Manual FM 90-10, Military Operations on Urbanized Terrain (MOUT):
The decision to attack or defend an urban complex can result in massive damage and destruction. Constraints on firepower to insure minimum collateral damage within its built-up areas can be expected. Combat operations may be hampered by the presence of civilians in the battle area. Concern for their safety can seriously restrict the combat options open to the commander. The necessity to provide life support and other essential services to civilians can siphon off a substantial amount of military resources and manpower. A hostile population may also impose a serious security problem. Success may well be measured by how we accomplish our mission while minimizing destruction of buildings and alienation of the population. On the urban battlefield, advantages and disadvantages in the areas of mobility, cover, and observation tend to even out for attacker and defender. Initially, however, the defender has a significant tactical advantage over the attacker because of his knowledge of the terrain.
In addition to the current battle, other urban operations of note include the Battle of Mogadishu during Operations Restore Hope in Somalia (1993) and the Battle of Hue during the Vietnam War (1968). In both instances, the United States inflicted tremendous losses on the enemy but suffered serious political setbacks.
The Battle of Hue was part of the Tet Offensive in the Vietnam War. Communist forces took the city and carried out a massacre of those they considered "cruel tyrants and reactionary elements." South Vietnamese forces and U.S. Marines counter-attacked to retake the city. In the end, 150 Marines, 400 South Vietnamese troops, and an estimated 5,000 Communists were killed. The body count and the success at securing the city suggested a victory for the United States, but television coverage of the battle was widely regarded as speeding the American public's rejection of the war.
In Mogadishu, at least 500 Somalis were killed in a fierce urban battle prompted by a mission to capture two of Somali warlord Mohamed Farah Aidid's aides. But eighteen Americans were killed in what was supposed to be a humanitarian assistance mission and television captured the image of one of the Americans being dragged through the streets of Mogadishu. In spite of the tactical success acheived by the mission and relatively small number of American casualties, most Americans--and most Somalis--regarded the battle as a defeat for the world's strongest military.
American military leaders are well aware of the history of MOUT. The heavy use of air power prior to the onset of ground operations in Falluja suggests that a decision was made to give greater weight to protecting American, British, and Iraqi forces than Iraqi civilians. Given the importance of winning the hearts and minds of the Iraqis, such a strategy is risky. Of course, the alternatives carry different risks.
We will know soon whether the Battle of Falluja was a military success. It will take longer to determine if it was a political success.