WASHINGTON - An American-led attack on Iraq would be a three-dimensional fight, a synchronized ballet of lethality conducted with lightning swiftness.
Precision-guided weapons launched by ships and planes would obliterate key sites in Baghdad. Helicopter-borne troops and commandos would seize airfields and weapons depots. Armored units would rumble through the country from north and south.
As the United States moves closer to war, military officials and defense analysts describe the fast-paced attack the Pentagon envisions as "ferocious" and "highly kinetic."
Some liken it to the invasion of Panama in 1989, when U.S. air and ground units swept in to capture the country's leader, Gen. Manuel Noriega.
The objective would be the decapitation of Saddam Hussein's government, a quick takedown of the leadership apparatus by destroying the ability to issue orders to senior commanders and special units that keep the regime in power.
"You want to paralyze the enemy all at once," says retired Maj. Gen. Robert H. Scales Jr., a former commandant of the Army War College who wrote the official Army history of the Persian Gulf war.
The battle plan put together by military leaders headed by Army Gen. Tommy Franks incorporates air, land and sea forces, heavy firepower, precision weaponry and high-tech gadgetry, some in its infancy during the 1991 gulf war.
One weapon uses an electromagnetic pulse to fry the circuits of computers and military communications systems, particularly those in hard-to-bomb underground bunkers. A pulse bomb could be attached to a cruise missile; a more precise method calls for shooting the pulse in a beam from a military aircraft.
Pentagon officials are debating whether to use it, some worrying that a pulse weapon could damage the electronics of Iraqi civilians or U.S. forces.
On the ground
In all, the allied force is expected to number about 250,000, less than half the size of the contingent that drove Iraqi forces from Kuwait in 1991.
The main thrust of the ground attack would come from Kuwait in the south, officials say, with other troops approaching from the mountainous north, either from Turkey or the Kurdish region of northern Iraq, should Turkey balk at accepting U.S. forces.
American commandos would slip in from Jordan or Saudi Arabia, hunting for mobile Scud missiles that could be fired at Israel or creating small forward bases.
The U.S. force assembling in the region includes the 4th Infantry Division from Fort Hood, Texas, the Army's most sophisticated heavy armored unit.
The battle plan calls for the division's tanks to sweep from the north along a route that might put them in contact with Hussein's elite Republican Guard near Mosul or Kirkuk. The armored force might also move south toward Hussein's hometown of Tikrit, about 100 miles from Baghdad, then drive on to the capital.
From the south would come the bulk of the U.S. force - the Army's 3rd Infantry Division from Fort Stewart, Ga.; the 101st Airborne Division from Fort Campbell, Ky.; and the 1st Marine Expeditionary Force from Camp Pendleton, Calif.
That force would be joined by British units, including Britain's 1st Armoured Division, and a smaller Australian contingent. The troops would surge north to take Basra and other cities on the road to the capital.
Helicopter-borne troops of the 101st might leapfrog ahead of armored units, seizing bases for their tank-killing Apache helicopters.
A brigade of the 82nd Airborne Division from Fort Bragg, N.C., would take part. The 4,000 paratroopers could grab airfields or oil fields, or assist in the invasion from the north.
The 3rd Armored Cavalry Regiment from Fort Carson, Colo., with helicopters and tanks, would provide reconnaissance and attack capability. During war games in Germany, the brigade practiced securing chemical or biological weapons depots and assisting refugees.
Several thousand members of the Iraqi opposition who fled Hussein's rule and settled in the United States, Europe and the Middle East would act as liaisons, translators and guides for allied troops.
Khidhir Hamza, a former official in Hussein's nuclear weapons program who defected in the 1990s to the United States, says the Iraqi opposition's main jobs would be to assist in finding chemical and biological facilities, calming civilians and urging Hussein's officers to give up.
'The Ali approach'
U.S. military officers expect many Iraqi army units, made up mostly of draftees, to surrender, and say some of the elite Republican Guard might also lay down their arms.
"I think a lot will happen real fast here," says retired Rear Adm. Stephen Baker, an analyst with the Center for Defense Information.
William Arkin, a former Army intelligence officer, calls it "the Muhammad Ali approach to war - there is dancing all over and striking from all directions."
But Arkin does not see allied troops roaring swiftly into Baghdad. Instead, he says, it will be a "modulated" campaign that allows time for the Iraqi people to overthrow Hussein.
A key part of the strategy would be nonlethal action, including the most far-reaching psychological operation in history. Officials plan to snatch a dictator's key lever of power: access to the airwaves.
Radio broadcasts denouncing Hussein's regime and carrying Defense Secretary Donald H. Rumsfeld's Pentagon briefings are now being aired on Iraqi frequencies. Should war come, there would be more radio and television broadcasts from facilities in Kuwait and studios aboard C-130 aircraft.
The intent of the message would be to calm Iraqi civilians, telling them how to stay out of harm's way, and to encourage Iraqi commanders to surrender.
E-mail being sent to Iraqi officers urging them to give up quickly has garnered positive responses, officials say.
The Pentagon also plans to allow about 500 reporters to accompany allied forces. The decision to pair reporters with front-line combat units for the first time since the Vietnam War is driven by the belief that Hussein might try to blame invading troops for civilian casualties or damage to Iraqi cultural or religious centers, officials say.
In some respects the war has begun. Hundreds of thousands of leaflets have been dropped around Basra and other areas, warning Iraqi soldiers not to use chemical and biological weapons or repair anti-aircraft defenses.
Since fall, U.S. and British planes patrolling the northern and southern "no-fly" zones - set up after the gulf war to protect Kurds in the north and Shiites in the south - have taken a more aggressive approach.
Allied warplanes are targeting anti-aircraft guns, command-and-control facilities and fiber-optic lines that can speed communications in order to degrade Hussein's air defenses.
Retired Army Gen. Barry R. McCaffrey, who led the 24th Mechanized Division on the famed "left hook" sweep against Hussein's forces during the gulf war, says an effort to remove the Iraqi leader would require crossing hundreds of miles of difficult terrain and might produce some of the most intense fighting since Vietnam.
"There could be some knock-down, drag-out fights," says McCaffrey, particularly if the Republican Guard, among Hussein's most loyal and best-trained units, decides to resist.
No match, militarily
Still, McCaffrey, like many experts, says Iraqi forces cannot match U.S. power on the battlefield. "They don't have a good military option."
Analysts say Hussein would likely avoid engaging the U.S.-led force directly. Instead, Iraq could resort to urban warfare or other means to slow an advance: unleashing chemical and biological weapons; blowing up dams, bridges and oil wells; or forcing hundreds of thousands of panicked civilians to flee toward allied lines.
Militarily, it would not be a fair fight. Twelve years ago, American air and ground attacks destroyed 3,800 Iraqi tanks, while only 18 U.S. tanks were hit.
Today, Iraq's ability to modernize its military or even buy spare parts has been crippled by United Nations sanctions, officials say, though air defense is perhaps the most sophisticated element of the Iraqi armed forces, because of assistance from China and Ukraine.
At the same time, the U.S. military has evolved into a more potent fighting force, with more precise and longer-range weapons as well as improved high-tech communications and surveillance equipment.
Some M1-A2 Abrams tanks have better armor, along with shells that can travel farther and pack a more lethal punch. Computer screens have supplanted paper maps. Glowing icons show the precise location of enemy and friendly tanks.
In the most modern tanks, a gunner can fire at a target while the vehicle commander, seated next to him, peers through his scope for another foe. With a flick of a switch, the commander's new target goes automatically to the gunner's viewfinder.
"You can acquire targets more quickly," says Lt. Col. Clay Miller, a product manager at the Tank Automotive Command in Warren, Mich. "It increases the lethality of the tank by 50 percent to 60 percent."
And here's a telling statistic: Less than 10 percent of the bombs dropped by U.S. aircraft in the Persian Gulf war were precision-guided, a number that rose to about 80 percent during the campaign in Afghanistan.
Some stealthy planes that have made their combat debut since the gulf war would play a key role in the fight, including the B-2 bomber, which can drop 16 bombs, each a 2,000-pound precision-guided weapon. The B-2 can also be armed with eight satellite-guided, 5,000- pound "bunker-buster" bombs that can pierce 30 feet of rock or reinforced concrete.
Moreover, unmanned drones have been upgraded to carry more-precise video cameras, infrared imaging systems and small bombs. They would keep watch over the battlefield, providing commanders with better intelligence and another way to kill the enemy.
Surveillance aircraft and satellites have spent the better part of a decade mapping Iraq and tracking movements of troops and trucks allegedly carrying banned weapons.
It is those banned weapons - chemical arms such as mustard gas and nerve agent, together with such biological threats as anthrax and botulinum toxin - that most trouble military officers and defense officials. Hussein's forces could launch a Scud missile or artillery round loaded with these so-called weapons of mass destruction.
To protect themselves, U.S. troops prepare to fight by taking vaccines and wearing chemical and biological suits. They deploy with sophisticated chemical and biological detectors; armored vehicles can be buttoned up against a poisonous cloud.
There are some in the U.S. military who believe that the chem-bio threat is overblown and say the Scuds and artillery can be located and destroyed before they can be used.
And chemical and biological weapons are an unpredictable battlefield tool, officials say. Weather conditions are a factor, and the poison load depends on an unreliable delivery system such as the Scud, a missile not known for its accuracy. Still, a chemical or biological attack could stall an allied advance and create a mammoth refugee crisis.
"If that happens, everything stops," says one Pentagon planner.
Officials also worry that Hussein and his most loyal forces might hunker down in Baghdad, forcing allied troops to root them out in a perilous building-to-building fight. Iraqi opposition sources and Pentagon officials are seeing defensive works being built inside Baghdad as well as Republican Guard movements that indicate preparations for a siege.
Scales, the former war college commandant, wrote in his book Yellow Smoke: The Future of Land Warfare for America's Military that urban warfare can be a "great equalizer."
Still, a sophisticated force such as the U.S. military can use intelligence assets and precision bombing to target "decisive points" inside the city, thus avoiding block-by-block combat, Scales wrote.
Moreover, Hussein is not a popular leader. He belongs to the Sunni Muslim ethnic group, a drawback when asking citizens - particularly the Shiite Arabs he has long terrorized - to take up his defense.
The Bush administration also worries that Hussein might adopt a "scorched earth" policy, destroying bridges, dams and oil fields as the allies press toward Baghdad.
The 3rd Infantry and other allied units have trained recently at erecting temporary bridges, and the needed equipment sits ready in Kuwait. Meanwhile, Pentagon officials say that commandos or light infantry units such as the 82nd Airborne might seize oil fields to prevent sabotage.
Blowing up dams - destroying water supplies for many of the 23 million Iraqi people - could boomerang on Hussein, military officials and Iraqi opposition leaders say, further alienating him from his citizens and even his armed forces.
War planners are going to great lengths to avoid civilian casualties and to deal with potentially huge numbers of refugees, officials say. Thousands of targets are being reviewed, spearheaded by "target boards" of military officers and civilian officials who decide which ones have military value and should be included on the list.
Three-dimensional computer models are created to look at each target to determine the best angle, bomb and fuse for an attack. Targets that could lead to civilian casualties require extra scrutiny and top-level civilian approval, officials say.
"No military in history takes more care to prevent civilian casualties than the U.S. military," said Jim Wilkinson, a spokesman for the U.S. Central Command, which is in charge of planning for an attack on Iraq. "However, when you're dealing with someone like Saddam Hussein, who has a history of using civilians as human shields, some civilian casualties may be inevitable."
Military officers realize that large numbers of refugees could slow an allied advance, tax allied supplies and focus the world's news media on the plight of dispossessed Iraqis.
The Pentagon and other U.S. agencies are stockpiling food, water and medical supplies near Iraq, and are outfitting a humanitarian crisis center in Kuwait, with the assistance of foreign governments and relief agencies.
Military logistics officers are trying to figure out how to truck in bullets and gasoline for troops while hauling food, tents and medicine for needy Iraqis.
Col. David A. Teeples, commander of the 3rd Armored Cavalry Regiment, which was ordered last week to deploy to the Persian Gulf, paused during war games in Germany to consider the prospect of an invasion of Iraq.
"I think the thing I would be more concerned about is civilians," he says, "more than weapons of mass destruction."