If rooting out Saddam requires urban combat in Baghdad, U.S. soldiers could face Iraqi snipers, ambush and even biological or chemical weapon traps lurking around every corner.
When it comes to urban combat, the U.S. military is haunted by memories of Mogadishu, Somalia, where a horrific 1993 battle that began with the crash of two Blackhawk helicopters in hostile territory left 18 American soldiers dead. The military disaster, which inspired the movie Black Hawk Down, also created a lingering distaste for urban combat.
"No prudent, experienced military commander looks at fighting in the built-up areas as anything but the worst of possible choices," said former Marine Lt. Gen. Gregory Newbold.
In Iraq, urban warfare would almost certainly mean face-to-face combat with Saddam's Revolutionary Guard on the narrow streets of Baghdad.
"The advantages that accrue to a defender in a city are that he fights from terrain that is very favorable," Newbold said. "That means buildings which offer him a high degree of protection from our precision munitions, from detection by our intelligence means and from fires by our ground forces."
But in the months before military action started, American soldiers have gone through intense, hand-to-hand urban combat training. Instead of following formulaic battle plans, soldiers are taught how to go into enemy territory with only one certainty: they won't know what is coming at them.
At Ft. Polk in Louisiana, soldiers undergo specialized urban combat training at the U.S. Army's Joint Readiness Training Center.
"We always train worst-case scenarios," said Army Staff Sgt. Rene Martinez. "It's a rude awakening sometimes, but it's a good awakening because the more they train on it, the better they get on it and they'll come back from a real-world deployment alive instead of in a bag."
Soldiers in the 509th Airborne Infantry based at Fort Polk are trained to think like the enemy. Then, 10 times a year, the soldiers put visiting units to the test in a plywood and cinderblock "city" called Shughart-Gordon. It is a $59 million facility named after two Delta Force soldiers who were awarded the Medal of Honor after they died protecting a downed pilot during urban combat in Somalia.
Mogadishu's painful lessons are passed on to each new group of infantry that enter the Shughart-Gordon battlefield.
In one exercise, the 25th Infantry Division, known as "Blue Force" for the exercise, tried to take the town. The sounds and sights of the battle seem real, though real bullets are replaced by blanks and smoke replaces artillery and mines. Simulated casualties were indicated by laser-tag type harnesses.
"It's as real as it gets," one soldier said.
Members of the division spent 12 hours putting their urban skills to the test, fighting in small numbers without backup, adapting to close quarters and even room-to-room fighting.
No Magic Tricks to Survival
There's no magic in how to survive. But there are techniques the Army believes can save a soldier's life and they are practiced again and again — like learning how to dance.
"Each man knows where he's supposed to go and if he messes up or has a brain cramp, another guy will pick up his slack," said Sgt. First Class Larry North, who ran urban combat training in upstate New York.
Unlike warfare in open terrain, for example, soldiers navigating a city move in three-or-four-man clusters called "stacks" — close enough to touch each other so they can stay together in smoke and in darkness without speaking.
By day and especially at night — when the U.S. military believes it has a huge advantage because of night-vision devices — the Army now spends more time training to fight in cities than in any other type of setting. Any soldier will tell you why.
"We train in order to fight," said Staff Sgt. Craig Jackson. "And if we don't do it and pound that type of attitude into their heads, we'll be combat ineffective."
Saddam’s ‘Dirty Tactics’
In addition to routing out the enemy on their home turf, U.S. soldiers will also likely be doing it all in the dark of night. Plus, it is highly expected that the opposing force will employ the so-called "dirty tactics" believed to be favored by Saddam Hussein.
Those tactics are something the U.S. military must adapt to.
"He has put aircraft around mosques, he's put anti-air defense weapons, tanks, artillery pieces around schools, hospitals," Newbold said.
At the end of the Ft. Polk exercise, despite their high-tech equipment and their training, the Blue Force was not able to control the town, but the good news was that "the enemy" bent on destroying the U.S. military were U.S. soldiers, too.
ABCNEWS' Chris Cuomo and John McWethy contributed to this report.