THE LAST US soldiers rolled out of Iraq across the border into neighboring Kuwait at daybreak Sunday, whooping, fist bumping and hugging each other in a burst of joy and relief.

Their convoy’s exit marked the end of a bitterly divisive war that raged for nearly nine years and left Iraq shattered, with troubling questions lingering over whether the Arab nation will remain a steadfast US ally.

The mission cost nearly 4,500 American and well more than 100,000 Iraqi lives and $800billion from the US Treasury. The question of whether it was worth it all is yet unanswered.

After a ceremony Thursday in Baghdad formally marking the end of the war, the timing and all other details of the departure of the last convoy were kept under tight secrecy out of security concerns for about 500 troops and more than 110 vehicles that were part of it. The low-key end to the war was just another reminder of how dangerous Iraq remains, even though violence is lower now than at any other time since the 2003 invasion.

The last convoy of MRAPs, heavily armored personnel carriers, made a largely uneventful journey out except for a few equipment malfunctions along the way. It was dark and little was visible through the MRAP windows as they cruised through the southern Iraqi desert. The 210-mile trip from a base in southern Iraq took about five hours.

When the convoy crossed the border into Kuwait around 7:45 am local time, the atmosphere was subdued inside one of the vehicles, with no shouting or yelling. Along the road, a small group of Iraqi soldiers waved to the departing American troops.

“My heart goes out to the Iraqis,” said Warrant Officer John Jewell, acknowledging the challenges ahead. “The innocent always pay the bill.”

Soldiers standing just inside the crossing on the Kuwaiti side of the border waved and snapped photos as the final trucks rumbled over.

‘I’m pretty excited’

“I’m pretty excited,” said Sgt. Ashley Vorhees. “I’m out of Iraq. It’s all smooth sailing from here.”

The war that began in a blaze of aerial bombardment meant to shock and awe the dictator Saddam Hussein and his loyalists ended quietly and with minimal fanfare.

President Barack Obama stopped short of calling the US effort in Iraq a victory in an interview taped Thursday with ABC News’ Barbara Walters.

“I would describe our troops as having succeeded in the mission of giving to the Iraqis their country in a way that gives them a chance for a successful future,” Obama said.

In the final days, US officials acknowledged the cost in blood and dollars was high, but tried to paint a picture of victory – for both the troops and the Iraqi people now freed of a dictator and on a path to democracy. But gnawing questions remain: Will Iraqis be able to forge their new government amid the still stubborn sectarian clashes? And will Iraq be able to defend itself and remain independent in a region fraught with turmoil and still steeped in insurgent threats?

Many Iraqis, however, are nervous and uncertain about the future. Their relief at the end of Saddam, who was hanged on December 30 2006, was tempered by a long and vicious war that was launched to find nonexistent weapons of mass destruction and nearly plunged the nation into full-scale sectarian civil war.

Some criticized the Americans for leaving behind a destroyed country with thousands of widows and orphans, a people deeply divided along sectarian lines and without rebuilding the devastated infrastructure.

“We are glad to see the last U.S. soldier leaving the country today. It is an important day in Iraq’s history, but the most important thing now is the future of Iraq,” said 25-year-old Said Hassan, the owner of money exchange shop in Baghdad. “The Americans have left behind them a country that is s falling apart and an Iraqi army and security forces that have a long way ahead to be able to defend the nation and the people.”