Army developed urban tactics, but lacked doctrine.

Urban warfare did not receive concentrated Army attention until the 1990s, despite a wealth of experience gained during conflicts spanning more than half a century.

Army doctrine has evolved into a focused plan of identifying, isolating and destroying concentrated targets within cities, rather than avoiding key population centers or storming them with all resources available.

It wasn't until quite recently that troops received realistic training in urban mockups.

In World War II, soldiers learned city fighting the hard way as they battled and blasted their way through the Ruhr and Manila, said Arthur Durante Jr., deputy chief of doctrine at Fort Benning, Ga., who has studied the history of Army urban warfare methods.

"But at the end of the war, we didn't have a doctrine. What we had were tactics. We knew how to do it. But we had never written it down, thought it through and said, 'This is why we do it this way, and this is how we ought to approach it.'"

The first manual for urban operations appeared in the 1950s. Solidly rooted in World War II experience, the book "Combat in Fortified Areas" focused more on tackling entrenchments than cities. "For 30 years, that was the only book," said Durante. "Good for what it was, but it talked about Sherman tanks against dragon's teeth and pillboxes on the Siegfried Line."

In 1979 came Field Manual 90-10, which reflected the change in Army focus from jungle warfare in Vietnam to mechanized warfare in Europe. And therein lay the problem. The manual used examples of village fighting in Germany-though West Germany had become heavily urbanized by the 1970s. "If you got down to it, the manual said, 'avoid fighting in cities," Durante said. "We bypass cities. We fight in the open. Cities are bad places to fight. Here are some things you can do if you're there, but don't fight there if you can avoid it."'

So the Infantry School came out with a supplement in 1982: FM 90-10-1, "Infantry Guide to Urban Combat." Though it focused more on city combat than previous works, it came out when the infantry was mostly stuck with M-113s instead of Bradleys and Abrams. "We were still back in the days of the Sherman," said Durante.

Perhaps worse, training didn't simulate urban combat. Durante recalled conducting lessons learned surveys of 7th Infantry Division soldiers who had participated in the Panama conflict. "One of the things that struck us was that we heard the same statement over and over again: they didn't have any idea of what the effects of their weapons would be against be against urban targets. When we went to the range, we shot at tank hulls and pop-up targets. We didn't shoot at cinderblock walls and car bodies."

He cited an interview with a platoon commander who had been ordered to secure a Panamanian water treatment plant. The gate was locked, so he fired a LAW anti-tank rocket at it. All it did was punch a hole in the gate without even destroying the lock.

"He told me, 'Honest to God, sir, I expected that gate to blow open, because that's what it does in the movies."' The platoon only entered the plant after one of the employees shouted that he had a key.

"They needed a picture in their mind, and the only one they had came from Hollywood," said Durante.

It wasn't until 1993, and the FM 90-10-1 supplement, "Infantry Guide to Combat in Built-Up Areas," that a current, comprehensive concept of urban operations began. Based on experience in Panama and Somalia, it "significantly increased our discussion of combat under restrictive conditions," he said. "We introduced the concept of high-intensity, precision and surgical operations, which were levels of violence and focused violence, as opposed to general attack."

Instead of bypassing or demolishing a city, current doctrine focuses on finesse and going for key "nodal points," such as communications centers and utilities. Combat is localized. "If he's concentrated his defense around an apartment complex of 25 or 30 small buildings, then you fight him there," said Durante.

In the 1990s, the concept of discriminatory engagement during room clearing operations also emerged. "Rather than just simply chucking in grenades from the outside until the screaming stops, we taught them to engage targets that need to be engaged, but don't engage others that don't need to be," Durante said.

The fundamentals of urban combat haven't changed much over the years, Durante said. Isolate, create breach, seize foothold, expand. But technology has changed some tactics. Instead of isolating a building with continuous artillery fire before assaulting it, UAVs enable commanders to call in fire only when needed.

Armor in urban terrain has become much more resilient. Durante admits that studying the disastrous Russian armored assault on Grozny in 1994 gave U.S. planners "an exaggerated sense of the vulnerability of armored vehicles in a large, modern city. So before Iraq, we had a little bit of reluctance to put heavy armored forces without a lot of dismounted infantrymen into urban areas." But superior American vehicles and training enabled U.S. armor to function where Soviet armor was slaughtered.

Sophisticated computer simulations and urban combat training ranges have replaced plywood village mock-ups. American soldiers are much better trained and equipped to deliver lethal force. "But the issue isn't how many we can kill," Durante said. "It's how many we can avoid killing and still accomplish the mission. We're much prepared doctrinally to pursue the full range of urban operations, which includes offense, defense, stability and support operations."