Before dawn, America's warriors were on the move, swift and mighty, in ships, planes, helicopters and armor and on foot.

Sunday, Feb. 24, was G-Day for half a million American troops across the Arabian sands and the Persian Gulf seas, the biggest ground offensive since Vietnam and their first desert war since World War II.Diplomacy had failed. The Soviet Union had tried to produce a withdrawal plan acceptable to both sides. President Bush said the last-ditch diplomacy gave Saddam "one last chance" to get out. Saddam didn't move.

More than 300 helicopters swooped down into Iraq under cover of night. Columns of tanks rolled across a 300-mile front from the Persian Gulf deep into Iraq, stirring up huge clouds of dust on the desert floor, shielded overhead by U.S. Air Force F-16A fighter-bombers.

U.S. Marines punched into the outskirts of Kuwait City from the eastern end of the offensive. And paratroopers of the 82nd Airborne Division dropped into the outskirts of Kuwait City, 50 miles north of the Saudi-Kuwaiti border.

WITH THE SEVENTH CORPS IN IRAQ - It's not easy to hide 145,000 soldiers and 75,000 vehicles in the vast Arabian desert.

But the commanders of the U.S. Army's VII Corps, assigned the central task of destroying the Republican Guard, credit such a massive deception with the decisive 100-hour victory.

It was a huge operation involving five divisions, most of which had not left their German garrisons since World War II.

When the VII Corps arrived in December, its thousands of pieces of heavy weaponry went right to the deserts south of Kuwait. They stayed there until 10 days before the ground offensive, then swung far west in the largest movement of ground troops since World War II.

The Iraqis were fooled into thinking the main thrust would come up the Wadi al-Batin, a dry valley that forms Kuwait's western border with Iraq and extends south into Saudi Arabia.

On the first day, the 2nd Armored Cavalry Regiment, the Corps' scouts, went into Iraq. Lack of resistance prompted the commanders to move the whole corps in at midafternoon Sunday rather than dawn Monday.

By Tuesday, the XVIII Corps had cut off all routes north to Baghdad, and the Air Force had left no bridges over the Euphrates River.

WITH THE XVIII AIRBORNE CORPS - Lt. Gen. Gary E. Luck tilted back the desk chair at his desert headquarters and said, with just a touch of a grin: "I'm going to sneak around behind 'em and surprise the hell out of them."

And that is just what the commanding general of the XVIII Airborne Corps did in steamrolling over the Iraqis.

In preparation, the corps moved 24,000 vehicles, 120,000 men and all their equipment 600 miles from the coast inland over an extremely limited road network in 16 days.

By all evidence, the Iraqis didn't know it.

Luck's mission was to sweep northeast to the Euphrates, then turn directly east like a spear between the Kuwait-Iraq border and Basra, southern Iraq's largest city.

The northeastward flanking movement of the XVIII Corps, combined with the push from the south by other major elements of the allied army, blocked escape for the Iraqis and put them in a killing box.WITH THE U.S. MARINES IN KUWAIT CITY - The 1st and 2nd Marine Divisions swept across the desert from the Saudi frontier in less than 60 hours, and drove through the Kuwaiti capital in a triumphal convoy.

The Marines seized the airport and launched a small, remote-controlled plane that photographed Iraqis scattering in all directions under intense bombardments.

At times during the advance, they reached speeds of 17 mph in their amphibious assault vehicles. At other times they were slowed, not by opposition, but by throngs of surrendering Iraqis, thick fog and pitch darkness at night caused by clouds blackened with smoke from burning oil wells.

Finally, unwilling to be slowed, the Marines began letting prisoners go. They gave the surprised Iraqis food, water and letters saying they had been processed, and told them to walk toward rear positions to be picked up later.WITH THE THIRD ARMORED DIVISION IN NORTHERN KUWAIT - It was a chilling view.

Looking south from the abandoned tank pits and bunkers built for Iraq's Republican Guard, it appeared that any attacking force would face huge casualties in carefully prepared killing fields.

Unfortunately for the Iraqis, their enemy didn't oblige them. Instead of attacking from southern Kuwait, U.S. forces swung in a wide arc across a desolate section of desert to trap them from the rear.

"You could see a lot of holes in the rear of Iraqi tanks," Nash said after viewing the battlefield.

Enemy artillery was unable to adjust to the fast-moving U.S. armored vehicles. Hundreds of Iraqi soldiers fled their vehicles and fortifications.

Where Iraqis did turn to fight, they were smothered by a combined barrage of artillery, rockets and tactical air support.WITH THE 1ST CAVALRY IN SOUTHEASTERN IRAQ - The 1st Cavalry Division knifed into central Iraq after spending more than a week as a decoy, a red herring meant to fool Saddam into thinking it would lead the land assault from a different location.

It had been just south of Iraq's southeast corner, along a dry desert gulch called the Wadi al-Batin that runs along the Iraq-Kuwait border.

For days, troops poured artillery into the area and sent scout patrols to give the impression the allies were clearing an invasion path.

Senior military officials said Iraq began reinforcing its troops there, apparently moving units in from farther west - where in fact the real invasion was planned.

When the land war began Sunday, the 1st Cavalry staged one more feint up the Wadi al Batin, its deepest yet into what were thought to be heavy concentrations of Iraqi forces. The 1st Cavalry then regrouped, moved west and punched into central Iraq.WITH THE 101st AIRBORNE DIVISION IN IRAQ - While the rout was under way in Kuwait, infantrymen of the U.S. Screaming Eagles were within 100 miles from Baghdad after an unprecedented assault deep into Iraqi territory.

More than 8,000 infantrymen were airlifted into Iraq over 72 hours of continuous operations.

They encountered little resistance and cut off Highway 8, a major route to Kuwait. They blew craters in the roadway, burned off the surface in places and burned at least 17 Iraqi trucks, leaving them to block the road.

The lightning strike began early Monday, when hundreds of helicopters moved the troops in what the division said was the largest airborne assault in history.

Their own success stunned the American troops.

"I still can't believe we got this far this fast," said Lt. Col. Hank Kennison, 42, a battalion commander from Lubbock, Texas.