The two week battle for control of Fallujah began long before the ground troops moved in earnest on November 8th. The intelligence troops did a great deal of preparatory work, which saved many lives and played a large part in the lop sided casualty rate (about 25 dead hostiles for every American killed). Resources available to the intel crew included constant aerial surveillance, some informers inside the city and the ability to eavesdrop on some of the enemy communications. This may have included some bugs placed inside the city, but no one is talking about that, or any of the other surveillance methods. What was used in Fallujah will be used again, and it dont work very well if the bad guys know what it is. Information was also obtained via dozens of large combat patrols that pushed into the city suburbs in October. These patrols forced the enemy to react, and this reaction was recorded and carefully studied.
The first thing the intel people had to find out what who was inside the city, what were they armed with, and how were they preparing to defend the place. Most published estimates put the enemy strength in Fallujah at about 3,000 armed men. That appears to have been correct, with some 2,500 gunmen killed or captured so far (and several hundred still hiding out among the civilians, or managed to have escaped the city.)
Finding out where the fighters were in the city was a more of a problem. The anti-government gunmen had been hammered for weeks by JDAM smart bombs directed at buildings they had taken over for living quarters. Taking over buildings was quite common. Sometimes the owners of the home cooperated, sometimes they were just kicked out. The gunmen preferred seizing a house in a residential neighborhood, believing that the Americans would be reluctant to bomb where there were a lot of civilians. The newly introduced 500 pound JDAM quickly destroyed that notion, and several hundred gunmen as well. Numbers are still being compiled on how many gunmen were killed in Fallujah before November 8th, either by JDAMs, or attacks by AC-130 gunships or AH-64 helicopters. There were often several attacks a night in the weeks before November 8th. This was not only to kill hostile gunmen, but also to disrupt the defensive plans for the city. The gunmen were getting pretty paranoid about all those attacks. Some innocent Fallujans were killed by the gunmen, who were quick to finger anyone as an informer. But a lot of the targeting information came from electronic and video surveillance. A couple of dozen guys moving into a building for the night left visual signs that could be captured and correctly interpreted. Tapping into telephones, and even the use of commercial walkie-talkies by the gunmen, also provided clues as to where some of these guys were going to bunk down, and often die, that night.
Despite the constant threat of death, and the knowledge that they were being watched, preparations were made to defend the city. But most of these were also observed, noted, and destroyed as the attack went forward. For example, surveillance revealed that several dozen car bombs were going to be prepared, for use against the invading Americans. Most of these were located after they were loaded with explosives, and parked somewhere. They were attacked from the air as the attack opened, and in almost every case there was a large secondary explosion, as the car bombs explosives detonated. The commanders of the troops going in had 3-D computer photos of the entire city, with defensive preparations and enemy troops concentrations noted. Movement was planned to minimize ambushes, and maximize movement by the attackers. Most of the planned ambushes, including over 600 roadside bombs and booby traps, were destroyed avoided because of this preparation. Bombs and various types of explosives were used to eliminate the enemy traps.
The enemy did have fairly elaborate plans for the defense of the city. They believed they could inflict lots of casualties on the Americans. But apparently the defenders of Fallujah had not paid a lot of attention to how American troops had fought in other Iraqi cities. The speed of the American assault, which was intentional, disrupted many defensive plans and maneuvers. Moreover, the American troops took prisoners early on, and many of these guys were willing to talk. The additional information on who was in the city and what they were planning to do was quickly used to make American operations more effective. For example, prisoners revealed where weapons, food and water had been stockpiled, to sustain drawn out battles. The enemy never got to make any costly, to the American, last stands. If there was a lot of resistance, the smart bombs or tanks would quickly demolish the building. Most of the fifty American fatalities were caused by enemy fighters getting off a few shots before they were spotted. And there were often leaders out front getting hit. One sergeant major, one company commander (captain) and eight platoon leaders (lieutenants) were killed. But the combat leaders had to be out front to keep the operating moving. Speed was life in this kind of fighting. Let the enemy get organized, and they become more lethal. Over a thousand enemy troops were captured, or surrendered, and many were in a state of shock at how quickly the operations moved. Moreover, combat went on at night as well. Fallujahs defenders were worked over in shifts, giving them little chance to sleep, eat or figure out what the attackers were up to (besides killing the gunmen quickly, and often while no Americans could be seen.)
A lot of American troops got hurt; about ten percent of the combat troops were casualties. But some 90 percent of the American casualties were wounded, while almost the opposite was true for the defenders. Part of this was due to the enemy gunmen often using false surrenders, or booby trapped wounded, to try and kill more Americans. These tactics worked sometimes, but too often backfired and made American infantry very careful around gunmen wanting to surrender. The defenders also thought theyd be able to use mosques as defensive positions. That didnt work. American snipers killed off a lot of gunmen inside mosques, and some mosques were bombed if they were being used to set up mortars. There were Iraqi commandos on hand, specially trained for storming mosques, schools and hospitals.
Fallujah was a battle won by better intelligence, as well as speed and superior training and leadership. The payoff was a huge amount of additional intelligence in the form of prisoner interrogations, captured documents and equipment. Moreover, the rapid, and one-sided nature of the battle, was a major blow to the Sunni Arab myth that they were winning their war to restore a Sunni Arab dictatorship in the country.