WASHINGTON - American soldiers approaching the outskirts of Baghdad are poised for one of the most dangerous and unpredictable operations of modern combat - a mission they are trained to perform but one that could easily lead to long days of fighting, indiscriminate destruction and casualties on a scale so far avoided in the high-tech age.
Instead of storming Basra and An Nasiriyah in southern Iraq, coalition soldiers were cordoning off those cities. But if Iraq's elite Republican Guard troops are entrenched in Baghdad as suspected - and if they choose to fight - American soldiers could soon wade into some of their heaviest and costliest urban combat since the Vietnam War's Tet Offensive in 1968.
The prospect of a battle over "Fortress Baghdad" is so ominous that some Pentagon officials say U.S. troops will take great strides to avoid it, perhaps by surrounding and isolating the city and waiting for it to "implode" under the strain. Superior technology and equipment give coalition forces an edge no matter the terrain, analysts say.
'The toughest battle'
But that edge is never thinner than when troops enter the cramped and mysterious confines of a large city such as the Iraqi capital.
"It's the toughest battle - certain to bring more casualties than we've seen," said Randy Gangle, a retired Marine Corps colonel who now heads a military think tank in Quantico, Va.
"If I were an opponent of the United States' military, then urban warfare is precisely the kind of battle I would want to wage. Nothing diminishes our superiority more than fighting inside a city."
Iraqi officials seem to agree. Speaking at a televised news conference in Baghdad yesterday, Iraqi Vice President Taha Yassin Ramadan suggested that President Saddam Hussein was hoping to lure coalition forces into an urban battle.
"We have allowed them to cross the desert," Ramadan said. "We wish and beg that they come to Baghdad, so that we will teach a lesson to this evil administration and all who cooperate with her."
The Pentagon has anticipated the need to fight in the streets of Baghdad since the war with Iraq was first contemplated. Few war planners expected Hussein's best troops to repeat the mistake of 1991, when they were pummeled by American B-52 bombers as they gathered in the desert.
But even as the U.S. military recognized the possibility of urban warfare, many of its actions up to now have been designed to rattle Iraqi troops into submission so that a battle in the streets could be avoided. The Pentagon's published urban warfare doctrine calls for attempting airstrikes or special operations before resorting to urban combat, because of the "terrible price" that city fighting has exacted in the past.
American forces have kept to the fringes of Basra and An Nasiriyah as they move northward, engaging in some urban battles but avoiding the kind of large-scale fight that might be needed to take the capital. At a briefing yesterday in Qatar, U.S. Lt. Gen. John Abizaid said Iraqi fighters are mingled with the population in those cities, making it difficult - and undesirable - to engage them in combat.
"We're not looking to go in and fight house to house in all these areas," Abizaid said. While acknowledging the risks, he called the coalition forces closing in on Baghdad "powerful and unstoppable."
If the troops approaching Baghdad are ordered into the city to sweep out Iraqi soldiers, they will enter the battle with little aerial intelligence and few clear ideas about where the enemy forces are and how well they are armed, analysts say. The aircraft and satellites that are so valuable in open terrain aren't so effective when enemy troops and weapons are hidden indoors or underground.
Artillery and airstrikes are less valuable in cities because spotters often cannot see their targets, and buildings shield enemy positions from bombs and shells. Likewise, the shuddering force of tank and mortar fire can shatter nearby buildings, endangering the troops around them. Soldiers who fire heavy weapons can suffer concussions and internal bleeding when operating from confined spaces such as a basement or a tight alleyway.
Urban warfare also forces soldiers to be perpetually alert and to make snap decisions. In contrast to the aerial bombardment of recent days, a typical urban firefight takes place at a range of under 100 yards, Pentagon planners say - often under 25.
"Urban warfare undoubtedly neutralizes some of our forces' superiority - not just in technology, but also our superiority in training, and in command and control, and in discipline," said Russell Glenn, a senior analyst who specializes in urban warfare at the RAND Corp., a research firm that advises the government on defense matters.
"Those superiorities still exist, and they give us the upper hand," Glenn said. "But you certainly could suffer far more numbers of [American] casualties than we've seen in ... recent years."
The complexity of urban warfare is one reason it has occurred so seldom in modern American history. Apart from relatively small operations such as the invasion of Panama in 1989 and the battle in Mogadishu, Somalia, in 1993, U.S. forces have not waged a major urban warfare campaign since the two-week fight in the Vietnamese city of Hue during the Tet Offensive. That bloody door-to-door battle, though an American victory, helped turn public sentiment against the Vietnam War.
The 'urban triad'
Unlike battles in the open desert, fights in a city must be planned around buildings, infrastructure and civilians - obstacles the Pentagon refers to as the "urban triad." This often creates an insurmountable conflict between the immediate needs of the military and the desire to rebuild structures and relationships later.
Pentagon strategy often calls for reducing enemy strongholds to rubble with artillery and air power. But urban fighters are told to first evaluate targets based on their cultural importance or proximity to civilians. In fighting yesterday outside Basra, Iraqi troops reportedly moved heavy equipment into residential areas to hinder the coalition's advance.
The balance between military objectives and civilian quality of life could be especially hard to strike in Baghdad, a city of 5 million residents. Not only is the United States promising to manage the city's civil affairs upon arrival - a task made more expensive and difficult if the city is smoldering - but its troops are also claiming to fight on behalf of the citizens of Iraq. America's role as liberator will be hard to defend if it leaves Baghdad in ruins.
Complicating the U.S. task, Iraqi troops are reportedly planning to use civilians to shield military sites. It is a tactic that American soldiers have encountered before. In Mogadishu, the enemy sometimes fired from within groups of women and children, forcing U.S. soldiers to choose between endangering themselves and possibly killing civilians.
"You have to train soldiers not to hesitate when they see something like that - to go ahead and shoot," Glenn said. "I don't mean to sound insensitive, but that's the kind of difficulty you're faced with in urban combat. A lot of times, there are just no good options."
Tactics have changed considerably in recent years, as the Defense Department has placed more emphasis on urban combat training. No longer do Americans roll through an urban battlefield room-by-room, hoping to secure and seal off the entire city one building at a time. Current policy calls for troops to establish and protect a small control base within the city, then send out random patrols to key areas.
Also, U.S. soldiers are no longer taught to flush out rooms with grenades, but rather to use small arms and rifle fire to discriminate between enemy soldiers and civilians. Also gone is the World War II-era practice of driving tanks through buildings to avoid exposure in the streets. Besides causing an inordinate amount of destruction and civilian deaths, that tactic ignores what the Pentagon has come to consider an imperative of urban warfare - men and tanks working side by side.
A 1999 Russian assault on Grozny underscored the problem with using only tanks to fight on city streets. Chechen rebels with rocket-propelled grenades destroyed tanks at each end of the Russian columns, then picked off the vehicles trapped between them.
A typical American urban combat operation would see tanks flanked by infantrymen, with the troops protecting the tanks from overhead rocket launches and the tanks protecting the troops from ambush. It is a scenario that U.S. soldiers practice with increasing frequency, and one that analysts say will become ever more likely as the world's population increases and cities grow larger and more dense.
"Urban warfare is casualty-intensive, it poses significant danger to infantry and to noncombatants, but the reality of the situation is that wars are going to be fought in the cities more and more," Glenn said.
"We've become an increasingly urbanized world. The military simply doesn't have the option of saying, 'We're not going to go in there because it's too difficult.'"