By Richard Pyle / Associated Press

One lingering image from the 1991 Persian Gulf War was of terrified Iraqi soldiers waving their arms in surrender to an unmanned Navy reconnaissance drone as it skimmed overhead, videotaping the desert terrain.

That incident underscored a vast difference between the two sides -- the battlefield technology that enabled a U.S.-led coalition of forces to easily defeat a million-man army, then billed as the world's fourth largest, in six weeks.

Twelve years later, American surveillance and "smart weapon" technology is far more sophisticated and reliable, and the key to what U.S. planners hope would be an even swifter, more decisive and less bloody victory than Desert Storm.

Despite an already big buildup of U.S. combat forces in the Gulf region, experts say a new war will not be a throwback to the desert tank battles of 1991. Nor will it be another Afghanistan, although "special operators" -- Army Rangers 

and Green Berets, Navy SEALs or Air Force commandos -- could play crucial roles in trying to capture or kill Iraqi strongman Saddam Hussein.

"What we can expect this time is some increased kind of mobility from the U.S.," said Francois Boo, an analyst at Global Security.org, an Alexandria, Va.-based think tank. "The objective of this war is not to recapture some land, but to remove Saddam Hussein from power. That's the center of gravity, and that means Baghdad."

Even if Saddam anticipates that, "the idea is that the U.S. force will be so powerful, and so fast, and take him by so much surprise that the regime will collapse by itself," Boo said. This "plausible scenario," as he calls it, anticipates that Iraq's forces, much weaker than in 1991, can be bypassed without a serious fight.

As in 1991, any attack is sure to begin with precisely targeted U.S. air attacks to blind Iraq's air defenses, destroy communications and cripple Saddam's ability to fight back.

This time, the weapons are guided by global positioning satellites and include the Predator, the Air Force's multipurpose unmanned aerial vehicle; the Navy's long-range Tomahawk cruise missile used in the Gulf War and against al Qaeda in Afghanistan; and new or upgraded missiles that can be guided from air to target from as far as 15 miles away. They have already been tested in Afghanistan, Kosovo and against Iraqi air defenses in the no-fly zone.

"There will be an increased reliance on surveillance and intelligence means, and on precision-guided munitions. The point is not to destroy everything in sight but to take out specific installations and facilities," Boo said.

In making Iraq's anti-aircraft defenses the top priority, U.S. officials cannot dismiss the potential threat of chemical and biological weapons, which are hard to detect and can be delivered by several means, including the Scud missiles used in the Gulf War.

As for ground action, Boo said, the objective will be to "drive straight to Baghdad," and with overwhelming forces at the city limits, wait for Saddam's regime to crumble under the pressure. "Anything else will just be a diversion."

While protracted World War II-type street fighting is the Pentagon's "nightmare scenario," Boo doesn't expect it. "The whole theory is that by the time the U.S. military reaches the gates of Baghdad, Saddam will have surrendered, or will be floating in the Euphrates as the result of the Iraqi people revolting."

Other experts are skeptical of that -- or of a coup d'etat, given Saddam's record of purging aides he suspects of disloyalty. Former Secretary of State Lawrence Eagleburger says that if Saddam's generals tried to topple him, "they'd all be dead" before they succeeded.

America's state-of-the-art weaponry and forces would go up against an Iraqi foe that analysts now estimate at 400,000 troops -- less than half the 1991 strength -- and filled with reluctant conscripts; aging tanks plagued by spare-parts shortages; and an air force that fled to Iran in 1991 and remains there.

In Desert Storm, 10 percent of bombs were guided and overall target accuracy was less than half. Four percent of allied losses -- which included 148 Americans killed -- were from "friendly fire," and hundreds of Iraqi civilians were killed or wounded in several high-profile incidents, including a U.S. attack on a Baghdad bunker that had been targeted as a command center.

In Kosovo in 1999 and Afghanistan two years later, 60 percent of the bombs were guided -- 87 percent in the Navy's case -- and three-fourths hit the target, Pentagon studies said. Loren Thompson, a military analyst at the Lexington Institute, called that "the most accurate bombing campaign ever."

Even satellite-guided weapons are imperfect -- as shown in Afghanistan, where human error was blamed for misdirected bombs that killed civilians and allied troops. But officials say technical inprovements, and the use of GPS-equipped commandos to identify targets, minimize chances of unintended casualties.