From March 23 to May 12, 2008, US Army and Iraqi security forces engaged in an intense urban battle in and around Baghdad’s Shiite neighborhood of Sadr City. The battle forced units that had been mainly focused on counterinsurgency operations to convert overnight into combined-arms teams of armor and mechanized infantry and engage a large enemy element in a high-intensity fight in a city containing around two million noncombatants. The adaptions these units made and the results of this short but pivotal battle provide important lessons for future combat in dense urban environments.

Sadr City is a dense Shiite area in eastern Baghdad whose boundaries with adjacent Sunni-dominated neighborhoods represent sectarian fault lines. At the time of the battle, Sadr City contained an estimated population of between 1.6 to 2.4 million residents. Purpose built in 1958 to house a large population of migrants moving to Baghdad to look for work, it maintained near slum-like conditions from the time of its construction. It stands out on a map of Baghdad as a solid, compact square of streets arranged in a grid pattern. The neighborhood is made up of narrow streets and alleyways, spider webs of power lines, and mostly three-story or shorter buildings that range from simple cinder blocks to reinforced cement construction.

Containing around a quarter of Baghdad’s estimated population of seven million in less than five square miles, Sadr City is one of the most densely populated areas where the United States has ever fought. Its population surpasses those of the sites of other urban battles, such as Manila in 1945, whose pre–World War II population was an estimated 1.1 million, or Seoul in 1950, with one million residents. As a battlefield (both in 2008 and an earlier battle in 2004), Sadr City exceeded any other part of Baghdad, in terms of density of both population and structures, where fighting occurred during the 2003 invasion.

Amid Iraq’s worsening sectarian violence between 2006 and 2008, in Baghdad the two major combatants were the Sunni Al-Qaeda in Iraq (AQI) and Shiite Jaysh al-Mahdi (JAM). There were many other terrorist groups, criminal gangs, and war profiteers involved, but most either aligned with, or at a minimum chose not to compete with, AQI or JAM—largely out of fear for their survival. AQI was a militant Sunni terrorist network led by Abu Muṣab al-Zarqawi. JAM was the Shiite paramilitary wing of fiery cleric named Moqtada al-Sadr’s national political movement. Al-Sadr had a major influence on the large Shiite populations and associated JAM militias concentrated in Sadr City, along with those in the southern cities of Najaf, Nasiriya, and Basra. Northeastern Baghdad contained a large JAM presence within Sadr City, but also a large AQI presence in neighboring Sunni areas—Adhamiya to the northwest, Rusafa to the southwest, and Tisa Nissan to the southeast—and the boundaries between Sunni and Shiite neighborhoods were often only demarcated by single roads, making it a fertile sectarian battleground.

In late 2006, Thawra District—Sadr City, and two, smaller, adjacent areas—saw fierce cycles of attacks and retaliations between Sunni and Shiite groups. Both sides attacked civilians, Iraqi security forces (ISF), and US troops. AQI frequently employed vehicle-borne improvised explosive devices (VBIEDs) and other mass-casualty attacks that had strategic implications on perceptions of the war in Iraq. The bodies of victims of sectarian murders were found dumped in the streets daily, averaging 200–250 per month.

In early 2007, the United States implemented a surge of five additional brigade combat teams (BCTs)—about 30,000 troops—to Baghdad and Anbar Province in the country’s west to stop the sectarian violence that had pushed Iraq into chaos. Under what was called the Baghdad Security Plan, one of the surge brigades was assigned to Thawra District, although no US forces would be based in Sadr City itself. The unit implemented an aggressive plan to reduce overall levels of violence that consisted of moving into small outposts within the neighborhoods; using concrete barriers to construct checkpoints, safe neighborhoods, and safe markets that reduced the enemy’s ability to transport resources and to conduct mass-casualty attacks with VBIEDs and other weapons; targeting key insurgent leaders and groups; and improving ISF capabilities.

The role and effectiveness of concrete in reducing violence across Baghdad cannot be understated. Concrete barriers had been used throughout Iraq for years to reduce the threat of improvised explosive devices (IEDs) emplaced along major roads. But during the surge, concrete barriers were widely used to limit the enemy’s ability to maneuver freely across Baghdad. The first surge unit in Thawra District, 2nd Brigade Combat Team, 82nd Airborne Division, led by Col. Billy Don Farris, emplaced over thirty miles of concrete barriers. One of the first uses of concrete was to protect the Adhamiya neighborhood by building a three-mile wall around it—which would earn a nickname: the “Great Wall of Adhamiya.”

The barriers used to form the walls were named after American states to denote their progressive size. The smallest, Jersey barriers (three feet tall; two tons), were used to block roads and slow traffic approaching checkpoints. Medium to large barriers—Colorado (six feet tall; 3.5 tons), Texas (six feet, eight inches tall; six tons), and Alaska (twelve feet tall; seven tons)—were used to construct checkpoints and protective walls around markets, mosques, and other areas where crowds were being targeted by bombs and shootings. The Texas barrier, due to its width and ease of transport, among other reasons, was predominately used to create the safe neighborhoods. But it was the massive T-walls that were used to create coalition and ISF bases and to maximize protection and prevent infiltration. Similar in size to Alaska barriers, the massive twelve-foot-tall, six-ton T-wall, with its interconnecting edges, created an effective barrier.

The walls turned Baghdad’s densely populated urban areas into more manageable “gated communities.” Once a wall was completed, Iraqi Army, police, or paid local neighborhood militias (called the Sons of Iraq) could occupy check points that allowed them to identify outsiders, search vehicles, and restrict the insurgents’ ability to bring large explosives and other weapons from one area to another.

Insurgents and guerrilla fighters rely on their ability to move undetected among the population to survive and operate. The Chinese communist revolutionary Mao Zedong counseled fighters to move among the people as a fish swims in the sea. In Baghdad, concrete walls in the sea made it a lot easier to kill or catch fish by creating chokepoints in the terrain that restricted enemy freedom of movement. Using obstacles to restrict insurgent movement in urban military operations is not new. British forces used blockhouses, fences, or other barriers to interdict insurgents in the Second Boer War (1899–1902) and during the 1950s in Malaya. French forces used wire and other obstacles to cordon off entire urban areas in the Casbah during the 1957 Battle of Algiers. Concrete was the barrier of choice in the Iraq War.

By the end of 2007, the Baghdad Security Plan had significantly defeated, or at least neutralized, AQI and had decreased sectarian violence in Baghdad considerably. But JAM continued to use Sadr City as a base of operations to carry out strikes against ISF and coalition forces. While the American and ISF units in Thawra District had begun to isolate Sadr City with their safe neighborhoods and other lines of operations, JAM retained firm control over the population and the terrain.

Special operations and conventional forces conducted some raids against JAM leadership in Sadr City, but these were extremely dangerous missions because of how fast the militias could respond to any outside visitors. While these responses varied, a common tactic used by JAM fighters (similar to insurgent tactics in 1993 Battle of Mogadishu and 1994 Battle of Grozny) was to allow the raiding force to enter Sadr City and then barricade the streets behind them (using tires and other debris). This funneled the raiding force into IEDs and prepared ambushes. JAM would also use cranes to put car hulks on roofs, which JAM fighters would use as improvised fighting positions.

In October 2007, US special operations forces in Sadr City close to being overrun had to call in an airstrike. In so doing they killed a number of Iraqi civilians and sparked public outrage, fueled by wide media reporting of the event. In response, Iraqi Prime Minster Nouri al-Maliki placed Sadr City off limits to US conventional units except under the most extraordinary circumstances. It would remain under such restrictions for the duration of the US military’s presence in Iraq.

With these political restrictions in place, one of the only things US forces could do to affect Sadr City was work to influence the flows—of fighters and weapons—going in and out by blocking some roads and building small joint security stations (outposts manned by both US and Iraqi forces) and checkpoints along the major routes.

Successes in reducing the leadership, capabilities, and influence of AQI after the surge allowed the Iraqi government, mainly under the direction of Prime Minster al-Maliki, to focus on other threats to Iraq’s stability, specifically the Shiite militias. The Iraqi government made plans as early as January 2008 to conduct a major offensive against the Shiite militia stronghold in Basra, Iraq. Two days before the attack, on March 25, JAM militias launched attacks in Baghdad with the hope of halting or diverting resources away from the planned offensive.

The Battle Begins

The violence that erupted on March 23 surprised the US forces in Thawra District; the strategic and operational context that drove the violence’s logic didn’t filter down to their tactical level. Their only warning was when their garbage wasn’t picked by a contracted trash collector at the same time it typically was each week. When they called him, he was adamant that he was not coming. Then all hell broke loose—not just in Thawra District but all around Baghdad, and especially in Sadr City.

JAM’s uprising included launching 107-millimeter rockets against targets in and around Baghdad, including the International Zone (commonly referred to as the Green Zone) that served as the central location of Iraqi government offices. They also attacked many joint security stations, ISF checkpoints, and police stations around Sadr City. The ISF, police, and Sons of Iraq manning these locations mostly collapsed or joined forces with the insurgents. By the time the Basra offensive commenced as planned on March 25, JAM forces had cleared the Iraqi Army and police from Sadr City, overrun half of the checkpoints that surrounded Sadr City, and increased their rocket attacks against the Green Zone. The Americans defended and reinforced where they could and began to receive reports on the size and magnitude of the attacks.

Prime Minister al-Maliki could not allow JAM’s rockets and uprisings to have a strategic effect on national governance by either derailing the Basra offensive or making the Iraqi government seem ineffectual in providing security. On March 25, he authorized ISF and coalition forces to undertake operations against JAM. The mission was simple: stop the rockets and restore government control in Sadr City. Importantly, he did not change the standing order preventing coalition ground forces from going inside of Sadr City itself. US units would have to fight an enemy who maintained a real physical safe heaven.

JAM’s estimated strength within Sadr City ranged between two thousand and four thousand fighters armed with AK-47s, PKM machine guns, .50-caliber sniper rifles, rocket-propelled grenade (RPG) launchers, 60-, 82-, and 120-millimeter mortars, 107- and 122-millimeter rockets, and an unknown number of SA-7 surface-to-air missiles. The group’s fighters also had a seemingly unending supply of IEDs, especially explosive formed penetrators (EFPs) made of machined copper plates and homemade explosives that form a shaped charge capable of penetrating several inches of steel. JAM fighters ranged from local men with little training and equipped with small arms to foreign-trained “Special Groups” and snipers with advanced individual military skills.

The mission of responding to JAM fell predominantly to the 3rd Brigade Combat Team, 4th Infantry Division, led by Col. John Hort, which had deployed to Iraq three months earlier and was responsible for the area around Sadr City. The two main units that would conduct the majority of the fighting were the 1st Battalion, 68th Armored Regiment (1-68 CAB), a combined arms battalion commanded by Lt. Col. Mike Pappal, and 1st Squadron, 2nd Stryker Cavalry Regiment (1-2SCR), commanded by Lt. Col. Dan Barnett.

The combat during the uprising was fierce. 1-68 CAB and 1-2 SCR responded immediately by attempting to re-secure the lost or abandoned checkpoints along Sadr City’s boundaries. Instead of insurgents fleeing when threatened with battle, they found JAM militants ready to fight, laying in hasty defenses, and attempting to mass against coalition forces. US platoons had to call in attack helicopters for support after finding themselves trapped by large groups of enemy fighters bunkered in multi-story buildings. Soldiers in one unit had 75–100 JAM fighters try to overrun them as they attempted to secure buildings around a soccer field that was being used as a rocket launching site. Luckily, Army attack helicopter teams were able to support the platoon and push the enemy back.

The intense nature of the fight caused 1-68 CAB to immediately transition to its fleet of M1 Abrams tanks and M2 Bradley infantry fighting vehicles (IFVs). They had parked these vehicles at Camp Taji, a large US base about a forty-five–minute drive away. Prior to the start of the battle, the battalion had traveled in up-armored High Mobility Multipurpose Wheeled Vehicles (HMMWVs), which were more appropriate to population-centric counterinsurgency operations. A normal patrol consisted of four HMMWVs and 16–20 soldiers. It took three to four days for 1-68 CAB to move and fully convert from a HMMWV-based counterinsurgency formation to an armored task force of Abrams and Bradleys. Patrols were organized at the company level to best use their equipment for the situation and urban environment. Bradleys, tanks, and armored HMMWVs were configured for best effect. For example, patrols consisted of one Bradley and two tanks or two Bradleys and one tank, with dismounted infantry in hunter-killer teams designed more for major urban fighting, rather than counterinsurgency.

Prior to the battle, 1-68 CAB had made numerous changes to the normal task organization of a battalion within a heavy brigade combat team (HBCT), which facilitated a quick transition to small-unit mixed armor and infantry teams. A standard CAB from an HBCT had two armor and two infantry companies as its major fighting forces. Normally these companies trained and deployed together, but are also designed to be capable of further task organizing to any variation the mission may require. When 1-68 CAB deployed into Baghdad, the battalion’s leadership quickly realized their armor companies did not have sufficient troops or vehicles to produce enough patrols to manage the considerable battlespace each was responsible for. Each company was therefore reorganized into three platoons; either one armor and two mechanized infantry platoons or two armor and one mechanized infantry platoon. Some companies were further stretched to four platoons. This gave each company the personnel needed to form large enough patrols and to have the total number of patrols needed to maintain a sustainable work/rest balance. But what it also did was create diverse teams of infantry and armor soldiers. Thus when 1-68 CAB converted back to armor and mechanized infantry teams, the command and personnel relationships were already well established.

As 1-68 CAB and 1-2 SCR continued to fight, the battalions’ higher headquarters during the battle, 3rd BCT, 4th Infantry Division, began to plan a movement-to-contact operation around and into parts of Sadr City to recapture all of the lost checkpoints and police stations. This course of action would have been a very destructive, high-risk operation. But the plan was shelved when ISF reinforcements arrived and quickly pushed into many of those locations so that at least the original checkpoints on the major routes into Sadr City were re-established. The mission was successful at pushing JAM back into Sadr City and even allowing for the return of some civilian activity that had ceased during initial days of the battle. Portions of Baghdad’s second largest market, the Jamila Market on al-Quds Street on the border between Sadr City and the Jamila neighborhood, slowly began reopening. But enemy forces maintained their sanctuary and showed their ability to attack at times of their choosing.

The primary mission for 3rd BCT was to stop JAM rockets from hitting the Green Zone. From March 23 to March 31, JAM launched over eighty-five rockets at the Green Zone. A major element of the BCT’s ability to go after JAM and the rockets was an unprecedented range of intelligence, surveillance, and reconnaissance (ISR) and strike capabilities, including: Joint Surveillance and Target Attack Radar System (JSTARS) aircraft; counter-battery radar; Global Hawk, Green Dart, Shadow, and Predator unmanned aerial systems, many armed with Hellfire missiles; Guided Multiple Launch Rocket System; air weapons teams of Army attack helicopters; constant Air Force close-air support; and Aerostat balloons and RAID camera feeds. Many of these were theater-level assets pushed all the way down to the brigade level. Previously, these would be considered division-level and above capabilities. But, in the fight for Sadr City, they were all under the BCT’s control. It took 3rd BCT’s headquarters at least three or four days to reconfigure itself to manage the large number of information feeds and assets now under the BCT’s control. Just identifying personnel to watch the different television feeds from the drones was a challenge.

Even with the most advanced capabilities available, stopping the rockets still required ground maneuver to seize rocket points of origin (POO). The plan to seize these locations, Operation Striker Denial, ran from March 26 to April 14. The US and ISF units conducted combined cordon-and-search operations on the neighborhoods immediately south of Sadr City that were within the maximum range of the enemy 107-millimeter rockets, taking advantage of securing key terrain that provided observation and fields of fire over the relatively level terrain. They occupied one of the few five-story building in the area immediately southwest of Sadr city, the Jamila neighborhood, establishing a patrol base with snipers on the roof. The building gave the snipers the ability to overwatch multiple POO sites and engage any positively identified combatants. Once the POOs were secured, they became a challenge to hold because of the enemy’s sanctuary. JAM fighters could easily slip and in and out of Sadr City, attack coalition forces, and then retreat back into their sanctuary. The routes to the POOs also had IEDs emplaced along them daily; US and ISF units would clear the IEDs one day only to find them there again the next.

While coalition forces were prohibited from going inside Sadr City, they maintained an impressive capability to see inside the city and strike when necessary. Persistent observation of all open areas in the city was aided by everything from balloons equipped with modern cameras and positioned just outside the city to loitering drones. The strike capabilities previously mentioned gave coalition forces the ability to strike any JAM forces that came into the open from their concrete sanctuaries.

The changing nature of the fight revealed that the Stryker vehicles used by 1-2 SCR were highly vulnerable to the EFPs and RPGs employed by JAM. 1-2 SCR lost six Strykers in six days. Not only were the vehicles not survivable, but their width (especially when fitted with RPG cages due to their vulnerability) limited them to driving on the main roads, making their potential locations predictable and susceptible to ambush. For this and other reasons, 3rd BCT, with assets provided from its parent division, made changes to both 1-68 CAB’s and 1-2 SCR’s task organization and battlespace. Major parts of 1-2 SCR’s assigned battlespace were given to 1-68 CAB, whose Abrams tanks and Bradley IFVs provided soldiers more protection and firepower to fight JAM. 1-68 CAB received an additional tank company and two additional Stryker companies. 1-2 SCR additions included an armor platoon that began leading patrols so the tanks could bear the brunt of attacks before they could destroy the Stryker vehicles. After reorganization, the 1-68 CAB and 1-2 SCR combined task force included nine companies. The total US forces numbered around three thousand, with an additional few thousand ISF depending on the phase of the operation.

Both of the assigned missions—to stop rockets hitting the Green Zone and to restore government control of Sadr City—were constrained by JAM’s ability to slip in and out of Sadr City to launch rockets from sites closer to their intended targets, lay IEDs, and attack coalition forces. One of the first coalition responses was to use concrete barriers to seal the individual routes leading out of Sadr City to the southwest, increase patrols of these areas, conduct ambushes on known firing points, and secure key terrain by, among other things, reinforcing ISF checkpoints.

These initial efforts were troop-intensive and not fully effective in stopping the flows of fighters, weapons, and rocket launches. 3rd BCT decided to construct a continuous wall made up of twelve-foot-tall, six-ton T-wall sections along the entire southern border of Sadr City on al-Quds street, named Route Gold on US military maps. Previous walls had been built along other portions of Sadr City’s boundaries that set the conditions for the planned operation. By this time, the areas bounded by Routes Grizzlies, Gold, Predator, and Pluto were mostly secured, but the effort was troop-intensive and JAM could still infiltrate in and launch rockets as well as plant IEDs and conduct other types of attacks.

On April 15, Operation Gold Wall was started. 1-68 CAB and 1-2 SCR conducted daily concrete-laying missions to construct the continuous wall. The desired purpose of the wall was different than that of previous walls built. Instead of protecting populations by keeping insurgents out of areas, the Gold Wall would be built to affect JAM while keeping them in Sadr City. Like medieval siege engines, the units formed each night in massive convoys consisting of a tank in the lead, flatbed trucks with concrete barriers, a civilian or military crane, Bradleys, and other vehicles.

The construction of the wall was heavily contested from the beginning. JAM’s first tactic was to establish a defensive zone by emplacing IEDs along the roads leading up to where construction of the wall would start that day. Because of these IEDs, the concrete-laying patrols had to first do a deliberate breach into the battle area. Streets were lined with trash, each pile a possible IED hiding spot. Combat engineers started by doing route clearance, but the normal procedures required them to stop at each suspected IED location, conduct a detailed search of the area, and, if an IED was present, neutralize the bomb (preferably done by attached explosive ordnance disposal teams) and try to render it safe for collection so that it could be exploited for evidence. The process could take hours for a single device. But JAM had lined the roads with IEDs. Some patrols would encounter twenty IEDs on a single street. US forces adapted with convoys developing new and faster methods. Tanks began to fire 120-millimeter canister rounds (in essence, shotgun-type rounds that, once fired, open into hundreds of tiny pieces) down streets from their main guns. The canister rounds blew the trash off the streets and, in many cases, exploded IEDs lying in wait for the patrol. If an IED was found, they would also shoot at them with 25-millimeter cannons and 7.62-millimeter machine guns to detonate them.

Once a patrol reached the site where the walls would be emplaced, the tanks, Bradleys, and infantry established overwatch positions for the crane and team of soldiers that would guide the massive concrete walls into place. Initially, JAM heavily targeted these patrols from within the city. This revealed their locations, though, and they were easily engaged. Some JAM militia fired from cover provided by buildings along Route Gold. Snipers would also shoot at the crane cable or the lone soldier that was forced to climb a ladder to unhook each concrete wall. Special operations forces snipers were extremely useful in a counter-sniper role. Nevertheless, there were situations where confirmed snipers and fighters that could not be engaged by US snipers had to be targeted with air-delivered, precision-guided bombs or Guided Multiple Launch Rocket System (GMLRS) rounds that could penetrate the buildings’ layers of concrete. One instance that required a concrete-penetrating option was when a JAM sniper occupied and fortified one of the few five-story buildings north of the Gold Wall was being constructed and at a key intersection where he was able to engage the wall-building team. Direct fire placed on the building did not affect the sniper’s fortified position. 1-68 CAB’s solution was to drop the building using the GMLRS. But for the duration of the Battle of Sadr City, coalition forces used fewer than three mortar or artillery fire missions because of the risk of collateral damage, the prospect of injuring civilians, and the potential political ramifications both locally for the government of Iraq and internationally for political support to the coalition forces.

The wall construction went slowly. At first, the wall was only constructed at night to take advantage of the American night-vision advantage. But when these forces would return to their bases after the nighttime construction operations, JAM emplaced more IEDs on the routes to the wall construction area. A decision was quickly made to transition to twenty-four–hour operations, rotating 1-68 CAB and 1-2 SCR every thirteen hours to give each patrol both daylight and nighttime hours. The number of concrete barriers that could be emplaced in a single shift varied greatly, depending on the enemy situation, number of tractor trailer vehicles to transport concrete from staging areas, and other factors. A bad night might not see a single barrier emplaced; during the most productive thirteen-hour shift, 105 were laid.

The logistical planning and execution of each barrier emplacement is an impressive case study in of itself. The number of personnel, vehicles, and refined tactics to safely emplace an average of over seventy barriers in a single shift is a lesson that must be captured for any similar future operations. A concrete holding area had to be constructed near Route Gold with a continuous flow of barriers and activity. Production at Iraqi concrete batching sites had to be increased. Each operation included a route clearance team to clear the route up to the wall; a security team for the holding area; a holding area team that included a crane, flatbed tractor trailers, and even two armored forklifts that in some cases transported walls all the way down to the wall site using already cleared routes; and a building site team (the main effort responsible for IED clearing around the site and construction of the wall) that included a crane, emplacement crew, and combined-arms team.

As JAM realized that IEDs were not going to stop the construction of the wall, the group’s fighters came out in force to fight the besiegers with direct fire. By so doing, they gave up one of the biggest advantages of being an urban fighter: remaining hidden by the city. Once JAM militia engaged the wall construction team, they became visible, easily identified, and targeted by the coalition’s far superior weapons and aerial ISR and strike capabilities.

While the decision regarding where to place the wall was based primarily on the maximum range of rockets targeting the Green Zone, one of the surprising effects the wall had on the enemy was cutting them off from their financial support. The Gold Wall on al-Quds Street not only separated Sadr City from nearby neighborhoods, which were more affluent and vulnerable to JAM extortion, but also cut JAM off from the Jamila Market, which was a major source of money. JAM extorted residents, merchants, and customers around the market area. The group also sold its own goods and weapons in the market. Coalition forces were not fully aware of the consequent effects on JAM finances before they started constructing the wall.

The militia had little choice but to “fight the wall.” Being sealed into the city would eventually force them to enter through heavily armed Iraqi Army checkpoints that would allow government forces to individually target them. It also would prevent their access to the Jamila Market and the population south of the wall. But most importantly, the wall would prevent the group’s ability to move fighters and weapons, conduct rocket attacks, and maintain a flow of resources, all of which were vital to JAM’s ability to function and retain influence.

As JAM members fought the wall, they continuously diminished their resources. In the beginning, JAM contested the wall with large groups of fighters. As the days and weeks progressed and the wall continued to grow, the numbers of fighters that would attack the siege party progressively got smaller. Coalition ground forces were successful at killing enemy fighters that contested the wall. At the same time, 3rd BCT also became increasingly effective at destroying rocket teams with the suite of persistent ISR and immediate precision airstrikes (from attack helicopters, fixed-wing aircraft, and drones) that they controlled. As the final barriers of the wall were emplaced, JAM appeared to have exhausted its supplies and fighters.

The positive effect of the Gold Wall is hard to argue. From the start of the operations on April 15 to late May, when the wall was connected to other walls that had been previously built or were simultaneously built around Sadr City, the number of SIGACTS recorded in 1-68 CAB’s area of responsibility—attacks and other significant events—went from of a high of 138 a week to just eight.

In just over a month, 3rd BCT had emplaced four thousand twelve-foot-tall, six-ton T-wall sections to construct a wall nearly three miles long. During the battle the BCT fired 120 Hellfire missiles, six Guided Multiple Launch Rocket System rounds, eight Air Force guided bombs, and over eight hundred 120-millimeter tank and twelve-thousand 25-millimeter Bradley cannon rounds. Precise JAM casualty numbers are hard to determine (especially since coalition forces weren’t able to go inside Sadr City to conduct battle damage assessments during the operation). Some reports estimated the number JAM fighters killed to be only 700, but it is likely that US and ISF soldiers killed, wounded, or captured thousands of JAM fighters.

On May 12, Muqtada al-Sadr announced a ceasefire. The final barrier of the gold wall was emplaced on May 15. Al-Sadr’s decision was clearly made from a position of weakness. JAM fighters within Sadr City had been neutralized. They were surrounded and effectively contained inside a concrete fortress. While the wall’s completion didn’t mean JAM was defeated, it did set the conditions for reestablishing government control of Sadr City. Iraq Army forces were ordered into Sadr City, but faced minimal resistance from JAM’s exhausted forces. Both Iraqi and coalition forces then exploited their success with major reconstruction projects that focused on local economics, government services, and infrastructure. They also transitioned back to counterinsurgency operations to maintain control of the gains they had achieved.

Lessons from the Battle of Sadr City

Context in war is everything. The political and military factors involved in the Battle of Sadr City—from the tactical to the strategic level—are in many ways unique. But there are also a number of urban warfare lessons that were learned (and in many cases re-learned) that need to be captured for consideration in future urban combat operations.

The history of urban warfare includes a wide variety of operations along the full spectrum of conflict (offense, defense, and stability). Since 9/11, the US military has predominantly been engaged in low-intensity counterinsurgency and stability operations, but the Battle of Sadr City was a high-intensity offensive mission against an enemy-held area.

Urban terrain gives a distinct advantage to a defender. Military or militarized forces that defend from cities seek to diminish the technological and numerical superiorities of an attacking force, especially ISR and aerial-enabled strike capabilities. Dense urban terrain limits the ability of military forces to maneuver. Hiding among buildings that effectively become concrete bunkers, defenders can funnel military formations into ambushes and terrain that breaks them apart, allowing them to be defeated piecemeal. A city’s maze of fortified structures also allows defenders to maneuver from building to building, often with prepared tunnels or holes in walls, to avoid air-delivered munitions or fixing forces.

Populated urban terrain, where it is extremely difficult to distinguish enemy forces from the civilian population, allows an insurgent to employ guerrilla tactics. These include anti-armor near ambushes, sniper attacks, and bombings. If engaged, enemy forces slip back into the population.

The entire environment establishes a military dilemma. The advantages that occupying a city gives to a defender will drive them to withdraw into cities. Likewise, the disadvantages for an attacker encourages most modern military forces to adopt an approach used historically, avoiding or bypassing cities whenever possible.

But warfare includes chance, and militaries often do not get a choice. When a war’s political objectives include destroying an enemy in a city, reclaiming a besieged city, or both, the military must accomplish the mission.

There are many mission-specific variables that will determine a military’s approach to accomplishing an urban operation. Among these are the amount of time and forces available to accomplish the mission, the viability of removing the city’s population, and political will in the face of the destructive nature of an urban battle. History shows that the most common approach a military force will take against any enemy-held urban area is to isolate or surround the city, remove as much of the population as possible, and then conduct costly, block-by-block, house-by-house operations until the enemy is cleared from the city. Because of the advantages afforded the defender, the attacker will typically have to use massive amounts of concrete-penetrating artillery and bombs that destroy most of the structures in the area of operations. This explains a US Army major’s remark during the Vietnam War’s Tet Offensive that “it became necessary to destroy the town to save it.”

These methods were used in most urban operations to retake an enemy captured city in recent history: Stalingrad in 1943, Hue in 1968, Grozny in 1994, and Fallujah in 2004. This is also the approach the world has witnessed in recent operations in cities occupied by the Islamic State, from Mosul to Marawi. But the 2008 Battle of Sadr City revealed a different approach.

Many of the lessons of urban warfare discovered in the Battle of Sadr City are enduring; others are unique to the context of the fight. Either way, it is important to ensure the lessons learned, or relearned, are considered by military thinkers when they face the next complex urban mission.

Strategically, the Battle of Sadr City reminds us that war is the continuation of policy by other means and subject to political control, objectives, and rationale. Politics and war are always intertwined. Military forces must account for national political objectives and constraints on the use of force when deciding on military strategy and tactics. In the case of Sadr City, significant political constraints were placed on the military.

Since coalition forces were not allowed to go into the city the enemy was using as a base of operations and safe haven, they were forced to create different options. They could not adopt the historical tactics of house-to-house clearing, particularly since the option to evacuate the city’s two million residents was not feasible because of the both the fragile sectarian security situation and political environment in Iraq. While 3rd BCT did execute information operations, telling civilians to leave or stay clear of the battle areas (especially the vicinity of the wall-building operations), the reality of the situation was that there was nowhere for the residents of Sadr City to go. Managing two million internally displaced persons was not something the government of Iraq was capable of, politically or logistically. Unable to clear the enemy safe haven, the military sought to isolate it.

Because of the local, national, and international political dynamics, coalition forces also further self-restrained their methods by only using wide-area effects weapons such as mortars and artillery in very limited circumstances out of concern over civilian casualties and the destruction of infrastructure. The risk to the wall construction could have been reduced with such fire, but it was not used. But, the need for concrete-penetrating munitions, which drove the use of GMLRS, for example, on enemy snipers deep within a five-story building, was consistent with previous urban battles.

Maintaining the political will to continue urban operations will often prove challenging, but will always be crucial. In the Battle of Sadr City, coalition forces had to worry about the will of their political leaders and casualty-weary populations; six US soldiers died during this battle. They also had to worry about Iraqi political will, as al-Maliki balanced fragile sectarian relationships and populations. Moreover, all perceptions were influenced by a globally connected world and 24/7 media reporting. Journalists were embedded with coalition forces during much of the battle. The total number of civilian casualties is unclear, but had destruction and civilian casualties reached a critical threshold, the military operation would have been impacted by further political constraints.

Operationally, it is important to remember that the Battle of Sadr City was fought within a greater campaign. It was influenced by all the other operations going on around the country (and vice versa). There were reports of JAM leadership asking for reinforcements from other strongholds, but those fighters were too busy fighting coalition forces and ISF in their areas. The Iraqi planned offensive against Basra was the spark of JAM’s uprising in Baghdad. A military commander’s ability to understand, visualize, and describe these connections will always be a challenge, and an important part of a commander’s staff’s focus in combat.

The Battle of Sadr City also strongly contests the overly simplistic notion that cities are sponges that soak up troops. Determining force requirements for urban environments cannot only focus on the size of the city and its population. The Battle of Sadr City saw a coalition force of around three thousand defeat an enemy of between two thousand and five thousand within an urban area inhabited by two million residents. The political objective, military mission, forces and tools available, enemy capabilities, security environment, terrain, and time needed to accomplish the mission all are more important factors than just the size of the city. A small military force can accomplish many missions in extremely large urban areas given the right circumstances and objectives.

The small American force in the Battle of Sadr City would not have been able to accomplish its mission without the unprecedented theater-level ISR and strike capabilities pushed down to 3rd BCT. The organizational flexibility necessary to make such changes and the skills required to manage those assets are all important lessons to institutionalize and consider when thinking about force size and design.

Tactically, there are many lessons from the Battle of Sadr City. Adaptions made by the units involved—across all of the Army’s warfighting functions (mission command, movement and maneuver, intelligence, fires, sustainment, and protection)—could be discussed at length. Selecting available capabilities, accounting for terrain considerations, and the use of concrete obstacles stand out as necessary highlights.

Military capabilities are about having the best tools for the job. The way military capabilities are designed is so when a formation faces a situation or environment it wasn’t prepared for, small-unit leaders can adapt their methods and their modular equipment. When a force faces an unfamiliar environment, it must be able to adapt. But good leaders and units adapt; great ones adapt quickly. The units of the Battle of Sadr City quickly adapted from counterinsurgency formations and methods to high-intensity urban combat.

These adaptations required employing equipment and weapons for different purposes than they were designed for, like using tank canister rounds to clear streets of IEDs. Adaptations also can call for completely different equipment. The fact that 1-68 CAB had its tanks and armored vehicles within reach—and had trained for high-intensity operations before its deployment to Iraq—allowed the unit to quickly transition from a counterinsurgent force into a combined arms team capable of high-intensity urban combat. Tanks and infantry fighting vehicles proved invaluable, while Stryker vehicles were found wanting in this environment.

It is not that the Stryker is not a useful vehicle. It offers a combination of speed, mobility, and transport options unlike that of other ground combat vehicles. But in “iron triangle” considerations (payload, performance, and protection) for vehicles in this environment, it did not provide the necessary protection against EFPs and was too wide for most of the urban terrain. Adding tanks that could lead the Stryker patrols was a successful adaptation to the Stryker organization. Other vehicle mixes and tactical changes were also required, such as emplacing Bradley IFVs in overwatch positions on high ground and using highly maneuverable armored HMMVWs to secure the rear of formations. Until the military deploys a combat vehicle more suited for urban terrain with mobile protected firepower capabilities, adaptable leaders and equipment sets will be required.

Concrete barriers deserve their own place in urban combat history as one of the most effective weapons of modern warfare—especially in the Battle of Sadr City.

Operation Gold Wall took many of the advantages of fighting in a city away from the enemy. The wall took the enemy’s ability to hide among the population, took away their ability defeat the attacker in detail with guerrilla tactics, separated them from multiple vital support lines, and forced them to fight. If JAM did not come out to resist the emplacement of the wall they faced isolation, being cut off from resupply, firing sites, and their critical financial base. When they did come out to resist, they became visible and were easily targeted by US ISR and ground forces. Instead of fish in the sea, they became fish in a barrel. Building a wall around the enemy’s base of operation created the conditions that made it both impossible for enemy fighters to operate effectively and possible to restore security to the broader population of Baghdad.

The use of concrete before and during the battle must be considered for future urban offensive, defensive, and stability operations. These lessons will quickly be lost if not written into doctrine. Creating a formation with effective siege-engine capabilities, able to emplace concrete walls safely and quickly, is both a science and an art. The technologies and tactics all played a role in the speed of wall emplacement and should be used as a starting point. But these methods could also be improved with planning, practice, and possibly new innovations.

Operation Gold Wall employed medieval siege warfare tactics with a twist. Instead of a city’s population withdrawing behind castle walls to wait out the besieging army, coalition forces brought a modern version of a siege engine up to the edge of JAM’s safe haven and built a wall around the enemy. This was very similar to the ancient tactic of circumvallation, an example of which was seen when Julius Caesar built a twelve-foot-high, eleven-mile wall around Alesia to defeat 60,000 Gauls in 52 BC.

Indeed, there are also lessons from ancient siege operations that could be applied to future modern urban combat operations. For instance, during the Middle Ages, a large wicker or wooden screen called a mantlet was placed in front of a besieging force’s engineers digging trenches up to a castle wall (an activity called “sapping,” the origin of the modern term “sapper”) to provide concealment and some cover from archers on top of the walls. The coalition forces’ concrete emplacement teams, especially the lone soldier that had to unhook the crane cable from the T-wall section, were extremely vulnerable. A version of the mantlet or modern sniper screens could be placed in front of the barrier operation to provide concealment from attack.

Even without a historical review, advancements can be made in countermobility, siege, and isolation tactics, especially those involving concrete barrier emplacement operations. Despite the years and miles of concrete operations in Iraq, no notable new technologies were deployed to assist in concrete emplacement. Concrete wall design did not change. Cranes were required to get T-walls off trucks and soldiers had to scale ladders to unhook them from the cranes. A closer examination is warranted, with the aim of enhancing the construction, transportation, and emplacement of barriers and walls.

The psychological impacts of the Gold Wall also warrant discussion. The wall clearly agitated the enemy and made JAM fighters come out and fight. The concept of imposing one’s will on the enemy goes back at least to Prussian philosopher Carl von Clausewitz. The actual act of imposing their will on the enemy by building the wall had a positive psychological effect on the coalition soldiers. It was a proactive action, fundamentally different than the reactive responses that had characterized day-to-day operations prior to the battle and especially the emotionally draining experience of waiting to get hit by IEDs without an enemy to strike back at.

The Battle of Sadr City also serves as a vignette to analyze urban terrain, both for the physical advantages and disadvantages it provides to both sides of a battle and in relation to the complex, social-cultural “system of systems” that are cities. Existing key terrain has to be properly identified and then utilized. Because Sadr City was purpose built, its buildings designed and construction relatively at the same time, its uniform layout of largely three-story structures made the few taller buildings key terrain that could be fortified and used as overwatch positions for key locations such as major intersections, ambush sites, or rocket-launching sites. Key terrain can also be created to shape a battlefield. The Gold Wall fell into this category, but attacking forces might also build a new piece of high ground with a new building, tower, or other structure. Finally, key terrain can also be removed, like when, during the Battle of Sadr City, attacking forces used GMLRS to reduce a sniper bunker in a five-story building. Beyond physical terrain analysis, understanding and balancing the relationship of a city’s systems to enemy and friendly forces will continue to be a vital requirement for the military. The financial and popular support provided by a very specific part of the city was a critical requirement for JAM’s survival, so much so the group gave up all the advantages of city warfare attempting to maintain control of it.

The US military prefers to avoid cities. But being a global superpower with complex and wide-ranging national interests means the military often does not get to choose where, who, or when it will fight. The Battle of Sadr City provides one alternative to traditional approaches to defeating an enemy force that has chosen to fight from within a city. It breaks the mold of avoiding cities because of the advantages it gives a defender, the troop-intensive requirements of attacking a city, and the destructive results of doing so. The use of combined arms maneuver (tanks and armored infantry fighting vehicles), massive ISR and precision strike capabilities, and elements of ancient siege warfare (walls) allowed a relatively small American force to contain, exhaust, and set the conditions to defeat a large enemy force within a populated dense urban area without destroying the city.

Special thanks to Dr. Dave Johnson, Col. (ret) Mike Pappal, Lt. Col. (ret) Rob MacMillan, Maj. John Chambers, and Command Sgt. Maj. (ret) John Kurak, who contributed to this article with their experience and research.

John Spencer serves as the Chair of Urban Warfare Studies as the Modern War Institute and Co-Director of the Urban Warfare Project . He is a retired Army major who served twenty-five years as an infantryman, including two combat deployments to Iraq. Follow him at @SpencerGuard The views expressed in this article are those of the authors and do not reflect the official policy or position of the Department of the Army, the Department of Defense, or the US government.

Featured image credit: Staff Sgt. Jason Bailey