RIYADH, Saudi Arabia -- The U.S.-led coalition launched an all-out ground campaign against Iraq early today, moving forces by land, sea and air just hours after a deadline passed for Iraq to withdraw from Kuwait, military officials said.
The invasion of Iraqi-held territory began about 4 a.m. (8 p.m. EST) and gave U.S. infantry and amphibious forces the cover of darkness for what Defense Secretary Dick Cheney described as a "massive ground operation," involving forces from several allied nations.
Mr. Cheney, speaking at a Pentagon briefing, announced a news blackout on all details about the campaign in order to prevent Iraq from gaining any knowledge about conditions on the battlefield. He said commanders assumed that Iraq remained "confused" by events, operations that are almost certain to include invasions occurring simultaneously along several routes.
The defense secretary said the ground operation was designed to cause a minimum number of allied casualties, but he described Iraq's estimated 500,000 troops in Kuwait as "well-equipped, well-fortified."
"I would not want to underestimate the difficulties of the task at all," he said.
Mr. Cheney deliberately left unclear the exact time when the ground assault began. But it apparently involved large numbers of forces that were activated at different times and began to move forward at varying speeds, according to a plan refined over a period of many weeks by officers at the U.S. military command in Riyadh.
Gen. H. Norman Schwarzkopf, commander of allied forces, chose the starting date and time well in advance of the operation's launch, and well before expiration of the deadline at 8 p.m. yesterday (noon EST) for Iraq to begin an unconditional withdrawal, Mr. Cheney said.
He said the schedule remained subject to change until the last moment, depending on factors ranging from the weather to possible diplomatic breakthroughs. "Up until noon today [Saturday], the president had the option to say, 'Stop,' " Mr. Cheney said.
U.S. forces began moving after armored units plowed through barriers to open the way for infantry, tanks and artillery to pour into Iraqi-held territory as part of a strategy to attack from several directions. In the hours leading up to the invasion, allied aircraft carried out a record number of bombing missions in and around Kuwait, targeting Iraq's best-equipped units.
President Bush said he authorized General Schwarzkopf to use "all forces available, including ground forces," to launch an operation that the president said would be carried out "swiftly and decisively."
According to Pentagon officials, reports from the United Nations that Iraq was willing to accept at least some of the conditions set by Mr. Bush were never reflected in the actions by Iraqi troops inside Kuwait. Rear Adm. Mike McConnell, the Pentagon's chief of intelligence, said, "We have seen no movement at all."
The timing of the assault appeared to be influenced by allegations that Iraq was carrying out summary executions of Kuwaiti civilians and systematically destroying the country's oil industry and drinking-water plants.
While officers in Saudi Arabia said yesterday that they continued to follow well-established battle plans, the pace of operations had accelerated throughout the day and appeared to be influenced by the allegations of Iraqi atrocities.
Marine Brig. Gen. Richard I. Neal, the U.S. military spokesman in Riyadh, said at a briefing yesterday that executions had begun within the last two days and were directed against civilians stopped at random as well as against people who had been interrogated in the past.
The reports of executions came one day after the military command said Iraq was setting fires to Kuwait's oil wells and destroying shipping terminals and other facilities, evidence that Iraqi President Saddam Hussein was carrying out a threat to keep Kuwait or destroy it.
Fires were reported burning at 200 wellheads, 50 more than the day before, and at high-pressure wells that could require weeks or months to burn themselves out. They spewed black smoke that colored skies a sickly gray as far away as the Emirate of Qatar, more than 300 miles to the south, and produced a thin rain of soot.
Smoke could hamper helicopters and aircraft assigned to support infantry by striking Iraqi tanks and artillery, but General Neal suggested that allied forces could avoid the affected areas and maintained that there would no significant impact on ground operations.
At least some of the smoke came from allied jets dropping napalm to set fire to trenches filled with oil. The military command was counting on being able to burn off the oil to undo Iraq's strategy of using the trenches to trap an invasion force.
Meanwhile yesterday, the command released new estimates of the effects of around-the-clock air strikes against Iraqi units. General Neal said the equipment destroyed included the following:
* 1,685 tanks, 39 percent of the estimated total of 4,200 tanks in and around Kuwait.
* More than 1,485 artillery pieces, 48 percent of the estimated total of 3,200.
* 925 armored personnel carriers, 32 percent of the estimated total of 2,800.
Those figures reflect the Pentagon's admission that some of its earlier counts of destroyed vehicles were too high.
After intelligence agencies objected to the original numbers, aides to General Schwarzkopf, the overall allied commander, agreed that some vehicles previously counted as tanks were in fact trucks and revised their earlier numbers.
The damage is not evenly distributed among the Iraqi units in the field. General Neal said some may have lost as much as 90 percent of their equipment while others may have lost only 10 percent.
TC "Obviously, every tank, every artillery piece, every APC [armored personnel carrier] destroyed, we're very pleased with," he said.
Iraq's losses in tanks and artillery from the air campaign might be higher than the latest figures because of the Iraqis' presumed inability to carry out repairs or even routine maintenance during more than five weeks of allied bombing, officers said.
"I would characterize it as an army that has had some severe losses," said Lt. Gen. Thomas Kelly, the Pentagon's chief of operations. "There are units in the theater of operations that have the capability to resist. I do not think they have the capability to prevail."
According to officers in Saudi Arabia, commanders recently changed the targeting strategy for allied pilots by switching the emphasis from bombing tanks to bombing artillery pieces, to reduce the number of guns available to fire chemical artillery rounds.
Pentagon officials warned that Iraqi field commanders using chemical weapons would be held personally responsible and pledged that a U.S. response would be "rapid" and "violent."
"They need to reflect in some depth on the wisdom of using chemical weapons against us, because we will not take that lightly," General Kelly said.
Military action yesterday seemed directed toward clearing paths for an allied invasion force. U.S. and British ships and helicopters swept for mines in waters of the Persian Gulf likely to be crossed by amphibious landing craft.
At the same time, allied aircraft flew a total of 2,900 missions. Pentagon officials said 1,200 went to Kuwait, the highest total ever for a 24-hour period. An additional 100 missions were targeted against positions of the Republican Guard, Iraq's best-equipped infantry and tank units.
Many of the latest efforts were designed to keep the Iraqis guessing about the allies' plans. For several days, the coalition has relied on air assaults by Marine Harrier jets, naval gunfire and deception to confuse Iraq about whether, when or where an 18,000-man Marine amphibious force would come ashore.
Maj. Gen. Harry Jenkins, the amphibious force commander, told pool reporters that several beachfront areas were being prepared for a landing and that the allies would direct heavy fire at several locations to complicate Iraqi efforts to learn where the actual assault would occur.
Artillery units were practicing similar tactics by firing over a large part of Saudi Arabia's border with Kuwait and Iraq. "I think they will wonder, 'Is this a large force out here that is about to make an attack, or is this sort of a diversion or a feint?' " said Brig. Gen. Nick Halley, an artillery unit commander.
At the Pentagon, General Kelly said a ground campaign would unleash the maximum possible firepower, dwarfing the violence unleashed by the air war.
"If the ground attack occurs, there will be no doubt in anybody's mind -- and especially in the mind of the Iraqi soldier -- that it has occurred," he said.
There were signs all along the front of ground forces inching forward, prodding here and there over berms of sand and rock. Troops with binoculars could see Iraqi soldiers well enough to help commanders direct mortar fire.
Troops and armored vehicles drove miles beyond the Saudi border and built at least one refueling stop for helicopters.
Signs of these missions showed up in unlikely places. On one truck, a message of bravado was traced in the dust, declaring, "This truck has been in Iraq."