Time has run out for Saddam Hussein. His 48 hours to leave Iraq are up.
More than six months after President Bush implored the United Nations to force the Iraqi dictator to disarm -- and two days after he gave Saddam a final ultimatum to go into exile -- a coalition of allied forces has massed along Iraq's southern border, prepared to attack on a moment's notice.
"At 8 o' clock tonight, the American people will know Saddam Hussein has committed his final act of defiance," White House spokesman Ari Fleischer said Wednesday afternoon in a news briefing. "I'm just not going to speculate as to what will or will not happen at 8 o'clock tonight."
He said Americans need to realize the war will not be without a cost.
"On the brink of war with Iraq, Americans should be prepared for what we hope will be as precise, short a conflict as possible, but there are many unknowns and it could be a matter of some duration," Fleischer said.
"Americans ought to be prepared for loss of life. Americans ought to be prepared for the importance of disarming Saddam Hussein to protect the peace."
Early in the day, American and British troops moved into the demilitarized zone separating Kuwait and Iraq.
An American military spokesman would neither confirm nor deny the troop movement. A British army spokesman said only that troops were in "forward battle positions." But high-ranking Kuwaiti sources confirmed the reports to Fox News, adding that Kuwaiti forces had not moved forward along with the others.
The DMZ, set up at the end of the 1991 Gulf War, extends three miles into Kuwait and twice as far on the Iraqi side. U.N. observers who were stationed there pulled out on Monday.
U.S. jets struck about 10 Iraqi artillery pieces in southern Iraq Wednesday afternoon. U.S. Central Command later confirmed that these guns were taken out with precision-guided bombs because they were within range of coalition troops on the Kuwaiti side of the Iraqi border.
U.S. and British jets have taken out surface-to-surface missiles in the southern no-fly zone before, but this marked the first time artillery pieces were targeted and destroyed.
In other developments, 17 Iraqi soldiers guarding the border defected and turned themselves in to coalition forces in Kuwait Wednesday evening.
The soldiers -- not technically prisoners of war, since the war has not yet started -- were believed to be the first Iraqis to defect. They are in the custody of the Kuwaiti border police, said Capt. Darrin E. Theriault, commander of the headquarters company of the division's First Brigade.
As the war begins, the U.S. military would prefer that Iraqi soldiers "capitulate" -- not officially surrender. Officially surrendering would obligate the United States to hold the men during the fighting as prisoners of war under the Geneva Conventions.
In an 11th-hour effort to avoid war, the Persian Gulf state of Bahrain offered Saddam a haven Wednesday. Arab officials said six non-Arab countries have also offered to take in the dictator.
State Department spokesman Richard Boucher said Wednesday that there's been no "serious proposal or discussion from the Iraqi side" that Saddam is considering the exile offer. Nonetheless, Boucher said, "let's hope he accepts, let's hope he shows interest and does what's best for Iraq. But at this point they don't appear to be interested."
Meanwhile, U.S. and allied troops made last-minute preparations for battle.
"Everybody's ready to go," said Command Sgt. Maj. Iuniasolua Savusa, of the 101st Airborne's 3rd Brigade at Camp New Jersey. "Things are going according to plan."
Near the war zone, U.S. Central Command Gen. Tommy Franks hunkered down with top military officers at the forward command center in Qatar, about 700 miles from Baghdad.
"He wants to make sure that the commanders have thought about every possible contingency that you can," said command spokesman Jim Wilkinson. "But he also is realistic enough, and has been around enough, to know that every military plan changes once the first bullet's fired."
Paratroopers of his 101st Airborne Division usually have a typical dinner of hamburgers or fried chicken, but on Wednesday night that fare was replaced with lobster and steak.
Checkpoints sealed the desert tightly as U.S. troops and armored vehicles rolled toward the Iraq border in the closing hours of President Bush's ultimatum.
A full moon -- not optimum conditions for a force that likes to attack by night -- rose in a sky without clouds but foggy with sand.
The 20,000 men of the Army's 3rd Infantry Division received some of the first orders Wednesday to line up near Iraq with their 10,000 tanks. Troops of the 101st were to be flown in on helicopters to seize key installations ahead of the 3rd Infantry Division.
"We will be entering Iraq as an army of liberation, not domination," said Capt. Philip Wolford of Marysville, Ohio, directing the men of his 4th Battalion, 64th Armor Regiment to take down the U.S. flags fluttering from their tanks.
After a brief prayer, Wolford leaped into an impromptu desert war dance. Camouflaged soldiers joined him, jumping, chanting and thrusting up rifles carefully emptied of their rounds.
Sailors aboard the aircraft carrier USS Kitty Hawk were advised how to administer drugs to counter chemical and biological attacks. Medical staff demonstrated the effects of chemical attacks -- including breathing difficulty and convulsions -- and how to treat them.
Self-injecting needles were distributed throughout the ship. Still, senior officers say a chemical attack on a ship is highly unlikely.
About 300,000 troops -- most of them from the United States, about 40,000 from Britain and some from Australia -- were waiting Wednesday within striking distance of Iraq. Backing them were scores of attack helicopters and more than 1,000 airplanes.
"Everybody's focused on what the mission is and what their part is," Savusa said. "We're just waiting on the word from our highers to execute our part."
One concern is that without U.N. troops guarding the Iraqi-Kuwait border, coalition troops assembling there may be vulnerable to Iraqi infiltrators who may run across the border and preemptively attack allied forces.
Spc. Chris Paxton, 23, of Dayton, Ohio, said he'd sent an e-mail to his wife, Julie, earlier in the day. "I just said I'd contact her as soon as I can," Paxton said, smoking a cigarette outside his tent.
"I'm definitely going to take an extra shower tonight and shave my head," he said.
Spc. Robert Worley, 24, of Daytona Beach, Fla., spent the day packing a military vehicle. He planned to call his parents early Thursday morning and tell them "just that I'm not going to call or write for a while."
"We're probably going to be living out of a truck for a while, sleeping in the sand," Worley said.
Sgt. Scott Wilson, 37, of Riverside, Calif., spoke with his wife and two children via a video conference call before returning to his cot and preparing his M-4 rifle for battle. "We don't know when, but we're just getting everything together," Wilson said.
With the war yet to start, some U.S. soldiers were already trying to envision its finish.
Marine Cpl. Nicholas Breitia's 15th Marine Expeditionary Unit has already spent 36 days in the desert. To break the monotony -- and the silence of the vast desert -- its 300 men gathered whooping and hollering for a company picture.
"I'm eager," said Breitia, 22, of Elko, Nev. "The sooner we get started, the sooner we get home."
Fox News' Adam Housley, Bret Baier and Greg Kelly and The Associated Press contributed to this report.