US Secretary of Defense, Robert Gates, has visited troops at Camp Ramadi in western Iraq to mark the formal close of the US combat mission and the departure of the top US war commander for the country.

U.S. Defense Secretary Robert Gates speaks during a change of command ceremony at Camp Victory U.S. military base in Baghdad, Iraq, Sept. 1, 2010. [Xu Yanyan/Xinhua]

Gates says that history will judge whether the war in Iraq was justified.?

Robert Gates, US Secretary of Defense, said, "Our men and women in uniform believe we have accomplished something that makes the sacrifice and bloodshed not to have been in vain. That we have accomplished, that our men and women in uniform have accomplished something really quite extraordinary here. How it all weighs in the balance over time I think remains to be seen."

Fewer than 50-thousand US troops remain in Iraq. Their main role now is to help train Iraqi forces over the next year. But Gates said the United States would consider keeping some military forces in place beyond next year, if the Iraqi government requests it.

Meanwhile, several thousand US special operations forces will continue to hunt al-Qaida and other militant fighters, accompanying Iraqi commandos. The US forces will remain armed, and will return fire or fight in self-defense.?