Quantico, Va. ? Despite the vast technological superiority of U.S. forces in potential combat against Iraqi troops, the prospect of a street fight in Baghdad makes American war planners shudder.

But that kind of warfare may be necessary to remove President Saddam Hussein from power. He has promised to take any war with the United States into his cities, and U.S. military and intelligence officials acknowledge that combat in Baghdad’s neighborhoods may be Saddam’s best chance to counter some of America’s military advantages.

Military strategists hate the idea of fighting in cities because it is so costly to both armies and civilians.

A defending force has many places to hide: buildings, rooftops, cellars. Streets turn into funnels for gunfire. Homes and parks become the front lines.

In a city, artillery bombardment and precision air strikes important aspects of U.S. military superiority carry with them the potential of heavy civilian casualties should a bomb go awry. Communications are spotty where there are tall buildings.

“You’re receiving fire from rooftops. You’re receiving fire from streets and windows, and sewers and cellars,” said Col. Frank Panter, who commands the Marine Corps Warfighting Laboratory at the Corps’ Quantico base, which studies urban warfare. “Any open area would probably become a killing field.”

An urban enemy has three weapons an AK-47 automatic rifle, rocket-propelled grenades, and a cell phone to coordinate attacks, Panter said.

A military adage says that an offensive force can expect to lose 30 percent of its troops taking a city. But some U.S. military planners are trying to overturn the old thinking by developing new tactics and technologies for urban combat.

Baghdad itself offers a diverse landscape for combat, a mix of modern wide boulevards and ancient side streets. It is divided by the Tigris River into western and eastern halves. Other waterways leave the older, eastern city essentially an island, reachable only by one of numerous bridges.

Most of the Iraqi government’s buildings, and Saddam’s palace, are on the west side. Baghdad’s civilian airfield is west of town; the interior of the city has two military airfields, one on each side of the river.

An invading force would find itself fighting in a first-world downtown, surrounded by third-world suburbs, said retired Marine Lt. Gen. Bernard Trainor, who last visited Baghdad as a journalist in the 1980s. It has a sewer system and some basements, but no subway system vital facts for planners who want to advise troops where to look for enemy attacks.

Baghdad’s outer reaches are defended by half of the Iraqi Republican Guard, amounting to three tank divisions, each with between 10,000 and 15,000 troops, U.S. officials say. The inner city is defended by an additional 15,000 troops in a paramilitary unit called the Special Republican Guard security forces picked for their loyalty to Saddam.

Retired Gen. Merrill McPeak, who headed the Air Force during the 1991 Gulf War, likens urban battles in Baghdad to “knife fights in a phone booth.”

“It would be a tremendous public affairs catastrophe if we start fighting door to door in downtown Baghdad and kill women and children trying to get Saddam,” McPeak said. “The frontal assault on the urban environment is doable, but we’d lose a lot of people.”

U.S. military experts say occupying Baghdad while minimizing deaths of U.S. troops or civilians will require some unconventional thinking for ground forces wedded the to the idea of combat in the open field.

One team of Marines at Quantico has a few ideas.

Assigned to “Project Metropolis,” these Marines study city fights of the past 60 years: bloodbaths like Stalingrad and Grozny, as well as urban conflicts such as those in the West Bank, Northern Ireland or Mogadishu.

Many of their ideas involve new tactics, rather than technology. Instead of using tanks or infantry alone, Maj. Dan Sullivan, the unit’s commander, proposes having them work together in teams as small as a single tank surrounded by a squad of infantry. The infantry provides the eyes; the tank, the muscle.

The challenge is that most infantry squad sergeants and corporals are not trained to operate with a tank at their disposal, nor are they experienced in how to call in artillery or airstrikes. Officers at higher echelons usually receive that training, Sullivan said.

Instead of moving in easy-to-target columns of troops around a city, Sullivan proposes having squads advance in random, snaking patterns in hopes of outflanking any potential ambushes.

Planners also are working on a small unmanned reconnaissance plane and a wheeled robot that can investigate dangerous areas without risk to the troops.