Saddam Hussein hopes to turn the battle for Baghdad into a Mesopotamian version of Stalingrad.
The Iraqi president is an admirer of Josef Stalin. He has modeled his ruthless rule and cult of personality on the Soviet leader. As the U.S.-led invasion force stretches its supply lines to reach Baghdad, military analysts and Iraq experts say Hussein's most loyal, best-equipped troops are digging in to try to inflict the kind of carnage that stopped Adolf Hitler at the Volga River in 1943.
A first and crucial test is likely to come near the cities of Karbala and Al Kut along a so-called "red line" that forms a ring south of Baghdad, where U.S. troops are massing now. If Hussein can avoid a military collapse there that would drag down his entire regime, analysts expect him to regroup his forces for street-to-street combat in the capital. And then, he appears to be counting on the modern weapons of media and world politics for his survival.
The Iraqi regime has spent years preparing for this showdown. Its strategists have researched U.S. military involvement in Vietnam, Lebanon and Somalia. Experts say videotapes of the movie "Black Hawk Down," which recounts the frenzied combat in Mogadishu in 1993, circulated among military men in Baghdad in recent months.
"People say to me you are not the Vietnamese, you have no jungles and swamps to hide in," said Tarik Aziz, Iraq's deputy prime minister, in an interview published recently by the International Institute for Strategic Studies here. "I reply, 'Let our cities be our swamps and our buildings be our jungles.' "
In tactics, technology and firepower, the force closing in on Baghdad is far superior to the U.S. military that fought in Vietnam, or the German army that slowly froze, starved and ran out of ammunition in the snow and rubble of Stalingrad. But Hussein's strategy relies as much on psychology as it does on armament.
The failure of the first Bush administration to finish him off in the 1991 Persian Gulf War convinced Hussein that his foes do not have the stomach for an ugly fight. Emboldened by the performance of his fighters in southern Iraq, he thinks he could negotiate his survival if his capital resists a siege for as little as a month to six weeks, said Toby Dodge, a professor at University of Warwick in Coventry.
Iraqi leaders hope gruesome televised images of civilian and military casualties will cause an uproar that forces the Anglo-American coalition to back down, analysts said. As far-fetched as that may seem to outsiders, what counts is that Hussein's regime takes the scenario seriously.
"I think that's crazy, but they believe it to their bootstraps," said Dodge, one of Britain's leading scholars on Iraq. "And with what's happened in the south, I think the Iraqi leaders have surprised themselves. If the Americans are getting that much flak from [Shiite] conscripts, it will be a hell of a fight when they get to the Republican Guard."
As the two sides prepare for heavy combat in and around Baghdad, experts debate two crucial issues. One is the ability of well-paid, highly motivated troops including the Republican Guard, a force of an estimated 70,000 soldiers and 700 T-72 tanks. The other is Iraq's possible use of chemical or biological weapons.
Although some Republican Guard commanders resent Hussein, they are also proudly professional and despise Americans. Past coup attempts by some units have caused the wary Hussein to station them along the "red line" outside of Baghdad. Experts expect this defensive outer ring of forces to engage U.S. forces near key points such as Al Kut, Karbala and the Euphrates and Tigris rivers.
During the first Gulf War, U.S. forces routed the Republican Guard, who were outgunned and tactically weak. But they also showed themselves to be disciplined and tenacious.
As U.S. forces bear down, the outer Republican Guard ring has two choices. It can attempt to hold its positions under a blistering onslaught. Or it can fall back toward the city proper, which is defended by the Special Republican Guard, a force that Hussein regards as staunchly loyal. Both tactics are risky.
Retreat could risk severed supply lines and confusion as the two Iraqi contingents meet, according to Michael Clark, director of the Center for Defense Studies at King's College in London.
"Once they start moving, they become more vulnerable," Clark said. "Even very well-disciplined armies have trouble merging together."
The next few days will be key, Clark said. If the Republican Guard can stop the Americans from punching a hole through their defenses, Iraq will win points in a propaganda battle focused on civilian deaths and, in some quarters, a perception that a brave underdog has stymied the most powerful military force in history.
On the other hand, if the attack rumbles forward with little difficulty, the military and political momentum will swing in the opposite direction.
Lawrence Freedman, another defense expert at King's College, said U.S. and British forces ought to be able to overcome the Republican Guards.
Iraq's defense minister conceded as much in comments Thursday. Sultan Hashim Ahmad Jabburi Tai told a news conference that the U.S.-led forces might well be able to surround Baghdad in the next five to 10 days.
"But they have to come into the city eventually," Jabburi Tai said. And when they do, he pledged that they will face street-to-street fighting that could negate U.S. superiority.
Hussein's past behavior and the dogged resistance in cities such as Basra, Umm al Qasr and Nasiriyah reinforce fears that the Iraqi leader is willing to use Baghdad's 5 million inhabitants as human shields. Soldiers, militia members and citizens there have been digging foxholes and erecting barricades.
Remnants of the Republican Guard outside of Baghdad are expected to join up with the Special Republican Guard and the Special Security Organization. Both forces are mostly led by officers from Hussein's Albu Nasir tribe and are showered with perks.
In addition, paramilitary units like those that have harassed U.S. and British forces in the south would play a similar role in Baghdad, ideal turf for hit-and-run tactics. Dodge said he has gotten reports that busloads of gunmen of the Fedayeen Saddam, as the paramilitary irregulars are known, are en route south from Hussein's native Tikrit to Baghdad.
The Special Republican Guard is a commando force of about 26,000 with about 100 tanks, as well as artillery and ground-to-air weapons. They have been groomed as die-hard warriors and would be deployed at key intersections for Hussein's last stand.
"They can substantially delay the advance of any force that tries to enter into the capital city," wrote Amatzia Baram of the University of Haifa in the International Institute for Strategic Studies journal recently. "They will not hesitate to use Baghdad's citizens as live shields and their loyalty to Saddam is, so far, solid. I believe that until it is clear to them that all is lost, they will fight."
Baram says the Special Republican Guard has orders to bombard the two main Shiite Muslim quarters of the capital, Madinat Saddam and Kazimayn where about 2 million people live, in the event of a revolt against the Sunni-dominated regime. The bloodshed could be blamed on the attackers, experts say.
The Iraqi regime's relationship with the Abu Nidal organization and other terrorist groups also raises the possibility of attacks by suicide bombers.
But urban combat holds risks for Hussein too. It will be harder for Iraqi commanders to control soldiers who might be tempted to desert or change sides. Close-quarter engagement will pose practical obstacles to use of chemical or biological weapons, which could endanger the very troops who unleash them, according to Sir Timothy Garden, a former marshal of the Royal Air Force.
Calculating the risks, U.S. generals could decide to encircle Baghdad and wait for the regime to crumble. In that scenario, Hussein's strategy would shift to politics and the media. Freedman and others said Hussein would hope for intervention by the United Nations, the Arab League and other foreign players to push President Bush and British Prime Minister Tony Blair to avert further violence
It is highly unlikely that the American and British leaders would back down, Freedman said, but Hussein might be right about their reluctance to launch a full-scale attack.
"The U.S Army is so obsessed with force protection that it's not bold enough," he said. "They will have to put people into awkward positions that are part of urban warfare."
In the event of a final charge into Baghdad to finish off Hussein, weapons of mass destruction could come into play. Hussein has steadfastly denied having them, but there have been scattered signs indicating that Iraq has prepared such weapons. The Republican Guard and other troops are said to be carrying gas masks and protective gear. A British unit found a petrochemical facility near Basra containing 23-foot, Scud-type missiles that could have been intended for chemical warfare.
And Britain's defense minister, Geoff Hoon, asserted Thursday that "significant discoveries in recent days," including statements from prisoners of war, show an intent to use nonconventional arms.
But some experts wonder if the regime really has weapons of mass destruction, or at least has them in usable form.
"Militarily, you'd think they would have used it already," said Charles Heyman, editor of "Jane's World Armies." "I'm beginning to think they don't have it."
Others think that use of such weapons is an apocalyptic last resort. If Iraq unleashed them after months of denials during the inspections process, the result would be to justify the U.S.-led invasion and spur France and other opponents of the war into supporting it.
Hussein's 2,000-strong Special Security Organization, commanded by the ruler's son Qusai, exerts tight control over the chemical and biological arsenal, experts say. The Iraqis are more likely to employ chemical weapons, because biological agents can take days to spread.
Lethal nerve agent VX and mustard gas could be used to create contaminated zones that coalition forces would have to avoid, a tactic that Iraq used in its war with Iran in the 1980s. Iraqi forces could also barrage attacking troops with rockets carrying Sarin or cyclosarin.
U.S. and British forces carry protection and decontamination gear, but an attack with chemical agents would slow them down or force them into detours. If troops are caught unprotected, the casualties could be widespread and have an acute psychological effect.
U.S. military planners believe that Hussein could feel enough pressure to resort to the doomsday option once coalition forces cross his defensive "red line."
"Saddam is being awfully careful to hold back," said Dennis Gormley, a senior consultant at the Monterey Institute of International Studies in California. "To use them would mean a shift of international opinion to the U.S. side. On the other hand, we're back at 'the red line' outside of Baghdad. It's the ultimate defining moment."
Staff writers Mark Magnier in southern Iraq and Maggie Farley at the United Nations contributed to this report.