Generals think of urban combat the way vampires view garlic. But in Fallujah, Iraq, U.S. forces have rewritten the book on urban military operations, producing what have been, so far, better-than-average results with lower-than-average casualties.

Military leaders hate fighting in cities because it's hard to find the enemy, to tell him apart from civilians and to use supporting weapons such as artillery and tanks. Combat can occur on multiple levels simultaneously (on the street, on rooftops, in basements), communication and resupply are difficult, and there really is no way to clear buildings except to send soldiers or Marines into them.

"A battle fought under these conditions lessens all the advantages the U.S. military possesses on the open battlefield, and requires that soldiers, not machines, fight and die for every corner, set of stairs, soda machine and hallway," wrote George Mordica of the Center for Army Lessons Learned in a 1999 paper. "The grim reaper will collect his due, no matter what devices can be developed to improve our advantage. There are just too many corners, stairs, vending machines and hallways along the way."

By historical standards, however, the grim reaper isn't doing well in Fallujah when it comes to collecting American casualties. Mop up operations continue, but the city is now controlled by U.S. and Iraqi government forces. They killed an estimated 1,200 resistance fighters, and captured 1,100 more in six days, a remarkably short time for a major urban battle, which usually are measured in weeks or months.

As of Friday, the re-taking of Fallujah was achieved at a cost of 51 Americans and five Iraqi dead, and about 425 wounded, of whom about a quarter have been returned to duty. Some 15,000 Marines, soldiers and Iraqi troops were involved in the attack.

"That kill ratio would be phenomenal for any battle, but in an urban environment, it's revolutionary," said retired Army Lt. Col. Ralph Peters, a respected military strategist. "The rule has been that the attackers would take about a quarter to a third of its force in casualties."

Civilian casualties in Fallujah were held down by the simple expedient of warning residents that the attack was coming and allowing them to leave the city. This approach had the down side of permitting terrorist leader Abu Musab al Zarqawi to escape, along with hundreds of fighters, and evacuating civilians is not always possible.

Lt. Col. Amos Guiora, an Israeli military lawyer, thinks the international laws that govern war, which were written to deal with conflict between states, need to be updated to reflect modern-day realities.

"Soldiers are trained to fight other soldiers," he said. "But that is not who you are fighting in Iraq or we are fighting in the West Bank and Gaza. We are fighting civilians, who look like innocent civilians until they start killing." New concepts of "active self-defense" need to be accommodated in international law to protect both soldiers and civilians, he said.

In Fallujah, the shooting of a wounded, apparently unarmed insurgent by a Marine as his squad was clearing a mosque might constitute "active self-defense" or a war crime, depending on whether the Marine had reason to think the man remained a threat. The incident is under investigation.

Whatever the circumstances of the shooting, the fact that it was filmed by a freelance journalist and shown over and over on Arabic television, enraging Arabs and Muslims throughout Iraq and the rest of the Middle East, represents a new factor in urban warfare.

"The big lesson is you have to [clear a city] fast because you are fighting not just the terrorists, but a hostile global media," Peters said.

Learning new lessons

Iraqi insurgents hoped to recreate in Fallujah a reprise of the 1994 battle of Grozny, which is also a city of about 300,000, during which Chechen rebels destroyed an entire Russian brigade of some 2,500 soldiers while Russian forces virtually leveled the Chechen capital. Military analysts say the Americans in Fallujah avoided the fate of the Russians in Grozny by carefully gathering intelligence over the two months preceding the attack; by innovative use of new technologies such as unmanned aerial vehicles; by being able to drop bombs and shoot artillery and even mortar shells with precision, and because of the superior training of American soldiers and Marines.

U.S. and Iraqi government casualties were held down by adopting tactics, first developed by the Israelis, to use bulldozers and tanks to clear routes through buildings to avoid ambushes set in the streets.

The Marine Corps, beginning in the 1980s, was the first American service to prepare seriously for combat in cities. Marine training focused first on preparing individual Marines for the rigors of urban combat, then small units, then larger units, culminating in a 1999 battalion-sized exercise in Victorville, Ca. called "Project Metropolis."

Basic Urban Skills Training for Marines includes firing paintball guns at each other through paper houses, said Maj. John Simeoni, an Australian officer at the Marines' Warfighting Laboratory in Quantico, Va. "They can't see through the houses, but they can shoot through them," Simeoni said.

The Army got serious about urban combat in the 1990s. Basic skills are taught in home units. Units deploying to Iraq or Afghanistan go through an extensive course at the Army's Joint Readiness Training Center at Fort Polk, Louisiana. With 18 mock villages and 200 Arabic-speaking role players, the training center prepares soldiers and small unit leaders for just about any contingency they are likely to encounter in Iraq.

The center constantly updates its scenarios, based on real world experiences.

"We've got 26 observer/controllers [instructors] in Iraq right now, gathering information on what worked and what didn't in Fallujah," said Lt. Col. Jay Peterson, chief of plans for exercise maneuver control.

Peterson, who served in Fallujah last year with the 82nd Airborne Division, said that as far as he is concerned, 51 U.S. dead may be a low figure by historical standards but still is far too high. He and his staff are studying ways to reduce friendly casualties in future urban conflicts.

Retired Army Col. Douglas Macgregor, a noted military reformer, said Fallujah could have been taken sooner, with fewer casualties, if the infantry had been provided more direct fire support and if small unit commanders had had direct access to video from unmanned reconnaissance drones.

One of the cable TV networks showed a general watching a live camera feed from an unmanned vehicle, Macgregor recalled. "It'd have been better if the feed were going to a platoon or company commander who could act immediately on the intelligence [the vehicle] was providing," he said. "Speed saves lives."

The Marine officer who commanded the attack in Fallujah claimed Thursday that U.S.-led forces had "broken the back" of the resistance. The insurgents had lost "your location and your means for command and control, you lose your lieutenants ... the turf where you're operating, the town you feel comfortable moving about in," said Lt. Gen. John Sattler, commander of the 1st Marine Expeditionary Force.

Others, including some Marine intelligence officers who work for Sattler, weren't so sanguine. The enemy has shown "outstanding resilience," and will be able to maintain a "sufficient level of intimidation" to "further degrade the capabilities" of Iraqi security forces in west central Iraq, said an after-action report they wrote.

John Thompson, a former Canadian army officer who is managing director of the Mackenzie Institute, is inclined to agree with Sattler.

"Historically, guerrilla forces have needed to inflict seven casualties for each one they suffer in order to remain viable," he said. "The insurgents have had a very bad week."