The last brigade of US combat has withdrawn from Iraq, bringing combat operation to an end in a war that has lasted more than seven years and claimed the lives of more than 4,000 US troops.

The brigade left the country in the early hours of Thursday morning, two weeks before an August 31 deadline for the end of Operation Iraqi Freedom pledged by Barack Obama on taking office.

Over the course the week soldiers from the 4th Stryker brigade, 2nd Infantry Division, have driven hundreds of vehicles from Camp Victory near Baghdad airport to Camp Virginia in Kuwait.

Their withdrawal brings to an end a controversial and bloody operation that began with the American "shock and awe" bombing campaign of Baghdad in March 2003, and saw the US military endure some of the heaviest fighting it had seen for a generation.

Captain Christopher Ophardt, a spokesman for the 4th Stryker Brigade of the 2nd
Infantry Division, said the last of the unit's vehicles will cross the border into Kuwait early on Thursday.

Iraqi concerns

Most of the brigade's 4,000 soldiers have been driving out of Iraq in their armoured Vehicles, with a few hundred members staying behind to finish administrative and logistical duties. They will be flying out of Baghdad later on Thursday.

About 50,000 US troops will remain in the country in an advisory capacity, helping to train Iraqi forces in a new mission codenamed Operation New Dawn, which will run until the end of 2011.

Al Jazeera's Rawya Rageh reporting from Baghdad said many Iraqis are concerned that Iraqi security forces are still lacking in terms of training and equipment, and particularly in intelligence gathering.

"Years of sanctions have made the population politically-savvy and many Iraqis are questioning the timing of the draw down five months after national elections ended in a political vacuum," our correspondent said.

"Many were worried about the possible increase in sectarian violence and the ability of Iraqi security forces to take the lead in the absence of US troops, and don't think this is a good time to be left alone without US military backing."

Al Jazeera's Josh Rushing reporting from the Iraq-Kuwait border said the question now is whether the drawdown, which is being touted as a milestone, will go down in history as the end of the war or the beginning of a period of violence.

"This is not the end of it. In fact, it will be a long military relationship between the United States and Iraq long after all US troops have pulled out of Iraq as scheduled in December next year.

"Iraqi military are using all US equipment and so their security forces will still need US trainers, technicians and links with the US military industrial complex in the years ahead."

Our correspondent said while the western media and history will consider the US war in Iraq a success, most people will be waiting to see what happens in the country in the coming months and years.

Campaign promise

Obama had made ending the Iraq war a central policy of his presidential campaign, and after taking office he immediately announced plans to bring combat troops home by the end of August this year.

He inherited around 144,000 troops in Iraq, 30,000 fewer than the peak levels of 2007, when the Bush administration ordered a so-called surge in an effort to improve Iraq's atrocious security situation.
After becoming president, Obama immediately set about transferring responsibility for security from the US military to Iraqi forces, gradually pulling US troops out of the country.

Generals approved the final tranche of the drawdown in May this year, despite a rise in violence following inconclusive parliamentary elections in March.

The war, which began when a US-led coalition invaded Iraq in 2003 and overthrew the government of Saddam Hussein, has proven costly to America both in terms of dollars and human life. Operation Iraqi Freedom has cost more than $900 billion and seen 4,415 US troops die.

That figure has been dwarfed by the number of Iraqi civilians killed, estimated at more than 100,000, according to the Iraq Body Countwebsite.
 
At the height of the violence in 2006, Iraq was brought to the brink of all-out civil war between the Sunni and Shia communities, with bombings and sectarian murders becoming a deadly part of day-to-day life many parts of the country. 

In 2007, President Bush ordered a controversial surge of more than 30,000 combat troops in an effort to improve the situation.
 
That, combined with improved cooperation with the Iraq's Sunni population, led to a substantial improvement in security that allowed US troops to begin transferring responsibility to Iraqi forces.

'Too Early'

While the end of combat operations will be welcomed by many ordinary Iraqis, US troops leave behind a country with a far from certain future.

Iraq has had no government for the past five months following the elections, and the security situation remains volatile, with a sharp spike in civilian deaths in July underlining the fragility of the situation.
Concerns have been raised that the US is pulling out of the country too soon, most notably by Lt Gen Babaker Zebari, Iraq's most-senior army officer, who warned last week that his forces would not be ready to take control of security until 2020.

Zebari predicted that "problems will start after 2011", referring to the Obama administration's deadline for the full withdrawal of US troops from Iraq.

In a graphic illustration of his point, a blast this week at an army recruitment centre in Baghdad left at least 60 people dead and more than 100 wounded, in one of the worst attacks to hit Iraq for months.

The Obama adminstration has defended its plans to withdraw from Iraq, insisting that it is satisfied with progress in the country, despite recent setbacks.

PHOTO CAPTION

The commander of American troops in Iraq, General Ray Odierno.

Al-Jazeera