John Spencer, Jayson Geroux, and Liam Collins | 07.25.23

The Second Battle of Fallujah occurred from November 7 to December 23, 2004 during Operation Iraqi Freedom. As noted in Urban Warfare Case Study #6 on the First Battle of Fallujah, which took place earlier in 2004, the city is situated on the Euphrates River in Iraq’s al-Anbar province, seventy kilometers west of Baghdad. It is a densely populated, industrial city with a long history dating back to its development as a way station along ancient silk road branches that connected Baghdad to major population centers such as Aleppo, Syria. In 2004, Fallujah had an estimated population of 250,000 to 300,000 residents. The city spanned about twenty-five square kilometers and consisted of over two thousand city blocks laid out in a grid pattern. The city had over fifty thousand buildings and structures, most of which were two-story concrete houses, but there were also some spacious homes, courtyard walls, half-completed dwellings, and multistory decrepit factories in industrial areas. It is bordered on three sides by prominent natural and manmade terrain features: the Euphrates River on the west, a railway with a raised railway berm on the north, and a major autoroute, Highway 11, running the length of its eastern edge. Highway 10, a six-lane highway, runs through the center of the city from west to east. The roads inside Fallujah included a mix of wide boulevards, narrow streets, and alleyways. At the time of the battle all were filled with heaps of garbage and wrecked automobiles, and some with rubble from the first battle.

The Battle

After the First Battle of Fallujah was prematurely terminated on May 1, 2004, the city was handed over to a newly formed Iraqi security unit called the Fallujah Brigade. But as the weeks passed it became increasingly apparent that this unit was not motivated to confront the insurgency. The brigade became incapable of controlling the city and many of its personnel deserted or sided with the insurgency as a result. Over the following months the insurgency strengthened, emboldening existing insurgents and attracting more fighters to their cause. The enforcement of strict Wahhabi law grew in the city and Abu Musab al-Zarqawi, the leader of what would become known as al-Qaeda in Iraq, was believed to have established his headquarters in Fallujah, which he used to plan attacks on coalition forces across Iraq.

The Iraqi Interim Government and the coalition realized that Fallujah could not remain an insurgent and terrorist safe haven. The Iraqis were holding their first post-invasion national election in January 2005 and the lawlessness and continuing attacks against coalition and Iraqi forces had the potential to undermine the election. More importantly, the insurgency could have been viewed as a genuine opposition power to the legitimate government if Fallujah’s citizens were unable to participate in the election. Such a demonstration that the lawful government’s authority was not recognized—much less exercised—in an important urban center could have severely undermined the new regime. Thus, senior American and Iraqi political and military leaders were incentivized to take the city.

Yet some leaders debated the merits of an attack and were concerned about the political ramifications of collateral damage. The coalition guaranteed the Iraqi government that it would provide humanitarian relief and reconstruction support to the damaged city during and following the battle to address concerns over the expected collateral damage. One of the biggest lessons from the First Battle of Fallujah was that Iraqis and coalition members had to deliberately shape the political environment to ensure the necessary political will to sustain the operation through its completion.

Once Iraqi and coalition leaders had established the political objectives and the parameters, American forces were finally allowed to begin planning. This second assault was initially named Operation Phantom Fury but was renamed Operation al-Fajr (“Dawn,” in Arabic) by the Iraqi prime minister prior to the attack to show that it was an Iraqi-approved operation. The primary objectives of Operation al-Fajr were similar to April’s First Battle of Fallujah: to defeat all opposition forces and occupy the entire city, clear out insurgent caches and the resources that were sustaining them, and eliminate the threat posed by Abu Musab al-Zarqawi.

The 1st Marine Division commanded Operation al-Fajr and assigned13,500 American and British troops and 2,000 members of the Iraqi security forces to the operation. American troops included two US Marine regimental combat teams and numerous combat support units, to include Marine civil affairs and Navy Seabees (expeditionary construction engineers). Regimental Combat Team 1 (RCT-1) consisted of two Marine infantry battalions—3rd Battalion, 1st Marine Regiment (3/1) and 3rd Battalion, 5th Marines (3/5)—along with the US Army’s 2nd Battalion, 7th Cavalry (Task Force 2-7) and Naval Mobile Construction Battalions 4 and 23. RCT-7 consisted of two Marine infantry battalions—1st Battalion, 8th Marines (1/8) and 1st Battalion 3rd Marines (1/3)—and the US Army’s 2nd Battalion, 2nd Infantry Regiment (Task Force 2-2). Supporting each RCT were engineers, military police, intelligence collection platforms, unmanned aerial vehicles, additional artillery, AC-130 gunships, attack helicopters, and fixed-wing close air support. Units of the US Army’s 2nd Brigade Combat Team, 2nd Infantry Division, 1st Battalion of the British Army’s Black Watch regiment, and Iraqi forces were assigned to isolate the city. Four Iraqi battalions were tasked to follow the American units and clear any structures that the American units bypassed during their advance.

By November, the number of insurgent fighters within the city had grown to approximately three thousand. While coalition forces were planning their attack, insurgent forces were busy planning and organizing their defense. Fighters fortified their defenses and constructed and implanted hundreds of improvised explosive devices (IEDs) made from propane bottles, gasoline drums, and various ordnance. They created mouseholes through walls within and between buildings and barricaded doors and rooftops. They dug trenches and tunnels under houses to use as escape routes and maneuver corridors to surreptitiously move between caches—some placed in schools and mosques—of weapons, body armor, and ammunition. They believed that the coalition attack would come from the south or southeast, so they concentrated most of their defenses on the southern and eastern edges of the city.

While planning for the battle, coalition forces carefully studied and applied lessons they had learned from the First Battle of Fallujah. One such lesson was that a successful attack on the city required sufficient time to gather intelligence, plan the operation, and prepare and position forces. As such, the coalition waited until November to initiate its attack. As a result, Operation al-Fajr included a thorough intelligence preparation of the urban environment; sufficient time for troops to prepare; an extensive shaping, deception, and information operations campaign; an impressive logistics buildup; and a careful fires support plan.

The intelligence preparation of the urban environment and training for the operation took several months. As part of the intelligence preparation process, coalition forces identified insurgent concentrations, command-and-control nodes, checkpoints, fighting positions, points of observation, possible sniper positions, roadblocks, weapons caches, and earthen berms, and disseminated the intelligence to the lowest levels during the weeks leading up to the battle. Throughout the month of October, the Army and Marine units had the necessary time to learn each other’s standard operating procedures and tactics, techniques, and procedures so that they were fully integrated by the start of the battle. The planning and training were designed to not only achieve a coalition victory but to do so swiftly as there was little appetite for a protracted urban battle.

Shaping operations were primarily aimed at convincing the civilian population to leave the city and to deceive the insurgents as to the main direction of attack. As such, deception and information operations played an important role during the operation’s build up. The deception plan ranged from distributing leaflets, building a fake military base, and conducting probing attacks on the outskirts of the city to make the insurgents continue believing the attack would be coming from the southeast.

Coalition forces committed significant effort to gain and maintain information dominance: they embedded dozens of journalists into the coalition units, and developed and executed an extensive media campaign to expose the violence perpetuated by the insurgents against Fallujah’s civilian population and Iraqi security forces. The information campaign also involved extensive actions to encourage the city’s civilians to leave before the battle. The campaign proved effective with only thirty thousand remaining at the battle’s start. This greatly reduced the incidence of civilians being wounded or killed and the likelihood that political pressure would once again prematurely end the battle due to a concern over civilian casualties.

The coalition staged a fifteen-day supply of rations, water, fuel, ammunition—over eleven million rounds—and other materials on the city’s edge so that they could quickly resupply frontline troops using armored vehicles and use these same vehicles to evacuate wounded personnel. The coalition also established maintenance points near the city to service vehicles so that they could return to the battle as quickly as possible.

The Marines finally initiated the assault on the evening of November 7. Task Force Wolfpack—which consisted of a company from the Marines’ 3d Light Armored Reconnaissance Battalion, a reinforced infantry company from 1st Battalion, 23d Marines, a reinforced mechanized infantry company from the US Army’s 1st Battalion, 9th Infantry Regiment, and the Iraqi 36th Commando Battalion—swiftly entered Fallujah’s west, at the bend of the Euphrates River, and quickly secured the hospital and two bridges that spanned the waterway. During its lengthy intelligence preparation of the environment, coalition forces determined that the insurgency was using the hospital as a military-type headquarters, so they sought to seize it quickly as coalition leaders feared the insurgents would publicize an extended attack on the hospital to sever political support for the operation, similar to what had occurred during the First Battle of Fallujah. Securing the hospital removed a critical command center and securing the bridges denied freedom of movement to the insurgents.

On November 8 coalition forces conducted a twelve-hour air bombardment focusing on the city’s south and southeast to make the insurgents believe the attack was coming from those directions. Also, having learned from the First Battle of Fallujah that it was an error to try to isolate the city through a series of checkpoints that could be easily bypassed, this time American, British, and Iraqi units isolated the city with units covering large sections of the outer perimeter physically or with observed firepower. American units were also dispatched to the Iraqi-Syrian border to close entry points and thus prevent foreign fighters who might attempt to reinforce the insurgents from entering. As a result, insurgents could not enter or exit the city or area without being checked or engaged by coalition forces. RCT-1 covered the city’s northwest and RCT-7 the city’s northeast, with their subordinate units extended in one long line from west to east—nearly five kilometers in length—across the city’s north.

Attacking from the north allowed coalition forces to avoid the insurgents’ strongest defenses—the deception plan had indeed helped convince the insurgents that the attack would come from the south or southeast. The Seabees and civil affairs cut the electrical power into the city to further hamper insurgents’ operations. That evening, all of the RCTs’ battalions breached the large railroad berm on the city’s north to start their break-in. For some units, however, the breach took much longer than expected, and 1/3 Marines had to use Task Force 2-2’s breach to eventually enter the city.

Throughout the evening of November 8 and well into the following day, Task Force 2-7 and Task Force 2-2 employed excellent combined arms techniques—employing infantry, tank, engineer, intelligence, and fires together—to break through insurgent positions in the city’s north. Some units only cleared buildings from which they received fire, bypassing the rest to move as rapidly as possible. Others chose to clear every building, which resulted in a more methodical and slower advance.

Allowing the battalion commanders to choose their method of advance, coupled with some units having armor or priority of artillery fires or close air support, did cause some challenges with the initial advance. Units with organic armor could quickly employ the tanks’ main guns to engage enemy strongpoint positions. Units lacking armor had to rely on artillery fires or close air support, which took much longer—especially if another unit had priority of fires and was calling for fire at the same time—because it takes time to clear fires, especially in an urban environment. For example, on November 9 in the city’s northeastern corner, Task Force 2-2, which had its own armor, moved much more quickly than 1/3 Marines, which had been slowed by the initial breach failure and also due to a lack of armor. This created a seam, and the enemy soon learned that it could move west of Task Force 2-2’s sector, and into 1/3 Marines’ portion of the city. Once Task Force 2-2 had bypassed them, the insurgents would then return to the task force’s sector, turn south, and attack the US forces from behind, or move north to strike 1/3 Marines from the battalion’s eastern flank as it advanced. This then forced Task Force 2-2 to turn around and return north to clear areas that had been bypassed. Despite these initial challenges, by the end of November 9 some American units had impressively reached Phase Line Fran (Highway 10), almost halfway through the city.

From November 10 to November 14 the American and Iraqi battalions continued their deliberate, methodical advance southward. Some districts offered only light resistance while others provided surprisingly heavy combat. To achieve success, the Americans employed a routine that has been common throughout urban warfare history and one that American soldiers had employed in Aachen during World War II and during many other urban battles. First came an airstrike, followed by artillery or mortars. Next, combined arms teams of armor, infantry, and engineers working in a symbiotic relationship of protection advanced down the streets. This was followed by infantry and engineers working together to breach into a building and clear the inside. The insurgents were unwilling or unable to launch night attacks, so the American units could post minimal security during these darkened hours while allowing personnel to rest, recover, and eat the food that was being brought forward according to the well-organized logistics plan.

Insurgents soon learned that fighting on the streets was a death sentence due to the coalition’s overwhelming firepower; thus, they generally chose to fight from inside buildings in individual groups of four to twelve personnel using small arms, rocket-propelled grenades, and IEDs. Fighters that engaged the attacking forces largely fell into two categories: guerrillas who tried to kill as many Americans as possible and then withdrew to fight again using hidden escape routes, and martyrs who tried to kill Americans and remained in place until they themselves were killed.

Like so many other urban battles, fighting was up close and personal, and the Americans learned to use overwhelming firepower—including tank and M2 Bradley infantry fighting vehicle fire, small arms, grenades, artillery, mortars, and fixed-wing gunships—to root out stubborn or hidden defenders. According to Canadian Army doctrine, offensive urban operations can consume up to four times more ammunition than operations in other environments because of the unique defensive qualities the physical terrain gives a defender and the ammunition needed to overcome those defenses.

In one example, one Marine tank company commander stated that during eight days of heavy fighting, his tanks had fired close to 1,600 main gun rounds, over 121,000 7.62-millimeter machine gun rounds, and over 49,000 .50-caliber machine gun rounds, with most of their targets being within two hundred meters. A Marine weapons platoon commander reported that each of his assault teams averaged using six explosive satchel charges, three cases of Bangalore torpedoes (to clear IEDs), and ten shoulder-launched weapons daily. Coalition forces fired over four thousand artillery rounds and ten thousand mortar rounds into the city. Aircraft and gunships dropped 318 bombs and fired 391 rockets and 93,000 machine gun rounds in support of ground troops. Fortunately, the strong logistics plan that had involved establishing commodity points just north of the city allowed for the continual resupply of ammunition, water, rations, and medical supplies without having to pause the advance, which would have allowed the insurgents time to regroup. As the attack advanced south, so too did the commodity points to ensure resupply and casualty evacuation remained quick.

Due to the challenges presented by urban terrain, there was a constant need for units to conduct face-to-face coordination through liaisons or staff connections to adjust boundaries; adapt tactics, techniques, and procedures; and conduct forward passages of lines to overcome the challenges and continue the fight. If the Marines lacked a particular enabler, such as an armored fighting vehicle or a particular weapons system, they could call on the Army unit in support to provide it. Likewise, if an Army unit lacked a particular enabler, the Marines were also obliging. As military researcher and writer Bing West observed, throughout the battle American Marines and soldiers “systematically went house to house, room to room, through thirty thousand buildings. . . . There had never been a battle that I have been able to find that was equivalent to this. One hundred squads had two hundred firefights inside rooms.”

By November 15 American officials announced that they had captured most of the city and were now only fighting isolated pockets in Fallujah’s southern area. American units now turned around, and with the support of Iraqi units, returned northward, carefully and methodically removing IEDs, weapons caches, and small pockets of resistance, work that would continue until December 23. Over the following months, the 4th Civil Affairs Group supported reconstruction and humanitarian assistance efforts and restarted essential services. Civilians were allowed to return after they passed through one of five entry control points and had conducted a security screening and there was an attempt to return the city to normalcy.

The fighting had of course come at a cost: 38 American, 4 British, and 8 Iraqi military personnel were killed and approximately 275 American, 10 British, and 43 Iraqi personnel were wounded. An estimated 1,000 to 1,500 insurgents had been killed and another 1,500 captured. Approximately eight hundred civilians were also killed. Similar to other urban battles, due to the overwhelming violence required to safely clear the city, over 60 percent of Fallujah’s buildings were damaged and 20 percent destroyed outright. Also, approximately 60 of the city’s mosques were heavily damaged.

Although the battle had caused an uproar within Iraq’s Sunni population—the Sunni Iraqi Islamic Party withdrew from the interim government, while the Association of Muslim Scholars’ three thousand Sunni clerics called for a boycott of the national elections and there was a low Sunni turnout as a result—the elections were still held in January 2005. The Second Battle of Fallujah became the heaviest urban combat that the United States had been involved in since the Battle of Hue in 1968 during the Vietnam War.

Lessons Learned

The First Battle of Fallujah provided many lessons that the American-led coalition documented, analyzed, discussed, trained on, and ultimately used to create an operational plan for the Second Battle of Fallujah. That process was vital to the second battle’s ultimate success. Yet many lessons—at the strategic, operational, and tactical level—can be learned from the second battle as well.

The first strategic lesson learned from the battle was that senior political and military leaders must be fully integrated into the planning and decision-making with full understanding of the time and costs needed to create and execute that plan. Political leaders rushed the Marines into the first battle due to the political pressure they felt to conduct a hasty reprisal against insurgents who had killed American military personnel and contractors. As a result, the haphazard plan and execution produced a series of negative outcomes. For the second battle, political leaders allowed the military several months to create an effective plan, which dominated the enemy in nearly every context: the coalition allocated sufficient forces for a city the size of Fallujah, conducted thorough intelligence operations, deceived the enemy, and controlled the information space. As a result, coalition forces were able to control most of the city after only nine days—an impressive feat given Fallujah’s size. Armies may want quick victories, but the challenges and complexities of urban warfare mean they are rare in the urban environment. Investing sufficient time to plan and prepare for the battle resulted in the coalition spending much less time fighting the battle. Time is a resource and operational and tactical units must be given enough of it to achieve strategic success in urban operations.

Successful urban operations also require an effective information operations campaign, and this is a second strategic lesson illustrated by the battle. Although effective information operations are necessary regardless of the environment, they are particularly critical in the urban environment due to the political significance of cities, the size and density of their civilian populations, and the interconnectedness of urban centers to local, regional, and global networks. During the first battle, the insurgents used multiple communication methods to portray events out of context and make the Americans appear as the more unethical actor. The political haste in directing the first battle had not allowed coalition forces the necessary time to create an effective information operations campaign to counter the insurgency’s propaganda. As a result, not only had the Americans been vilified internationally, but senior Iraqi and American political leaders became apprehensive about what the battle was doing to their coalition partnership. This resulted in senior political leaders micromanaging the battle and ultimately, ending it prematurely. The Americans’ haphazard attack was followed almost a month later by a withdrawal that allowed the insurgency to claim victory.

The coalition did not repeat this error for the second battle. They carefully integrated the information operations campaign into the operational plan, rather than having a separate plan that was bolted on afterward. This enabled the coalition’s extensive media campaign to expose the unjustified violence perpetuated by the insurgents against Fallujah’s civilian population before and during the battle. The information campaign also recognized the importance for complete transparency, so dozens of journalists were embedded into American units. Consistent messaging and transparency convinced most of the city’s civilians to flee the city before the battle. Ultimately, the information operations plan convinced both the Iraqi people and international audiences that the coalition was more ethical.

The first operational lesson from this battle was that urban operations require a thorough intelligence preparation of the environment from the operational to the tactical level. Again, time is a resource, and the urban environment is so complex with so much information to gather and so many factors to analyze that intelligence personnel—working closely with operational planners—must be given an extended period to collect and analyze intelligence that can used to develop an effective plan. The Marines that had been directed to hastily execute the first battle had only been responsible for Fallujah for approximately two weeks. Thus, they had little understanding of the city that they had been directed to swiftly enter and clear. For the second battle, the Americans spent from May to November conducting the intelligence preparation that was needed so that Marines and soldiers understood the city’s challenges thoroughly, and thus produced a plan that overcame many of these challenges. By the end of October, American intelligence had confidently located insurgent concentrations, command-and-control nodes, checkpoints, fighting positions, points of observation, possible sniper positions, roadblocks, weapons caches, and earthen berms. This information was pushed down to the lowest tactical levels so there were few surprises when it came to the enemy.

Units attacking a city must isolate it to prevent enemy reinforcements and resupply from supporting the fight, and this is the battle’s second operational lesson. During the first battle, only a single RCT consisting of four battalions was tasked to conduct the operation. The Marines had established a series of checkpoints in and around the city, but they were too far apart. As a result, enemy insurgents were able to enter and depart Fallujah undetected. Recognizing this shortcoming, the coalition moved a second RCT, a British Army battalion, four Iraqi battalions, and two Army battalion-sized task forces to supplement the RCT that owned the city for the second battle. As a result, there was a force that was large enough to isolate the city and prevent anyone from entering or exiting without being detected. Thus, by the end of the battle, the defenders had exhausted their resources—personnel, ammunition, water, rations, and medical supplies—and could not continue the fight. Throughout history it has been repeatedly demonstrated that if an attacking force can isolate a city, the battle will be shorter and victory more likely. Allowing the defender to reinforce and resupply by moving through gaps only elongates urban battles and makes victory less likely or more costly for an attacking force, due to consumption of more costly resources. Of course, such an isolation is extremely difficult and sometimes impossible for larger cities, in which case planners will have to divide a city into sectors and isolate those one at a time as the battle progresses.

Urban operations are resource intensive, so a good sustainment and logistics plan is critical. This is both an operational and a tactical lesson. According to Canadian Army doctrine, urban operations can create three to six times the number of casualties, consume four times the amount of ammunition, and require two-and-a-half times more water and rations per soldier than operations in other environments. Coalition forces learned this lesson during the first battle, so planners understood how important it was to stockpile supplies and have a good sustainment plan for the second battle, especially given the size of the force. It took time to locate appropriate commodity points, build them up, and store and protect the required supplies, and the Marines were given the necessary time. Like American logisticians from World War II, logisticians established their commodity and maintenance points just outside of the city so that units could be swiftly resupplied and personnel and vehicle casualties swiftly retired. As American units advanced, these commodity points also advanced to keep the resupply lines as short as possible. Of course, given the proximity of these locations to the front lines and the enemy’s ability to move through the urban environment unobserved, there will always be a need to protect commodity points and logistics personnel and their vehicles. This means combat training is required for logistics personnel or they must be given additional combat arms units to protect them. The benefits, of course, of having supplies close at hand is that it allows the attacking force to continue its offensive without a deliberate resupply pause, which increases the likelihood of success.

A second tactical lesson from the battle is that urban operations require effective combined arms maneuver employing all available enablers and, given the complexity of the urban terrain, these units need to be fully trained and thoroughly interoperable beforehand. Coalition planners realized they needed to dedicate more forces for the Second Battle of Fallujah so they assigned two combined arms task forces and many attachments to the RCTs, but these units had never worked together. The integration of the Army battalions within each of the Marine RCTs, and the sharing of enablers when needed, demonstrated an admirable level of teamwork. This allowed Marines and soldiers to forge strong bonds between units that always enhance the likelihood of combat success. All this integration allowed RCT-1 and RCT-7 to secure a fairly sizeable city in only nine days with only several additional weeks required to clear the city afterward. This is especially impressive given that urban battles often take several weeks or months.


The First Battle of Fallujah allowed the US military to collect extensive strategic, operational, and tactical lessons—discussed in the previous case study—that it applied and successfully executed during the Second Battle of Fallujah. Of course, no military operation is ever perfect, and there are still many lessons that can be learned from the second battle. While this battle is widely lauded as a success and a model to study, it is important to note that the coalition and Iraqi units were given many months to prepare for the operation as well as the necessary forces to execute it. Units will not always have these same luxuries in time and resources, so it is important for leaders to be sufficiently educated and their units adequately trained to conduct urban operations without having months to prepare. Because the 1st Marine Division was given the necessary time and resources for the Second Battle of Fallujah and took full advantage of this opportunity to execute a complex urban assault, the operation is worthy of study and is a model of success.

John Spencer is chair of urban warfare studies at the Modern War Institute, codirector of MWI’s Urban Warfare Project, and host of the Urban Warfare Project Podcast. He served twenty-five years as an infantry soldier, which included two combat tours in Iraq. He is the author of the book Connected Soldiers: Life, Leadership, and Social Connections in Modern War and coauthor of Understanding Urban Warfare.

Major Jayson Geroux is an infantry officer with The Royal Canadian Regiment and is currently with the Canadian Army Doctrine and Training Centre. He has been a fervent student of and has been involved in urban operations training for two decades. He is an equally passionate military historian and has participated in, planned, executed, and intensively instructed on urban operations and urban warfare history for the past nine years. He has served twenty-eight years in the Canadian Armed Forces, which included operational tours to the former Yugoslavia (Bosnia-Herzegovina) and Afghanistan.

Liam Collins, PhD was the founding director of the Modern War Institute at West Point and a Fellow at New America. He is a retired Special Forces colonel with deployments to Iraq, Afghanistan, Bosnia, the Horn of Africa, and South America, with multiple combat operations in Fallujah in 2004. He is coauthor of Understanding Urban Warfare.

The views expressed are those of the authors and do not reflect the official position of the United States Military Academy, Department of the Army, or Department of Defense, or that of any organization with which the authors are affiliated, including the Canadian Army Doctrine and Training Centre, the Canadian Armed Forces and the Canadian Department of National Defence.