Military officials say two brigades from the 101st Airborne Division will leave Iraq this month and only one will be replaced. A brigade is roughly 3,500 soldiers. Initially the 3rd Brigade, 101st Division, was scheduled to leave this month, and the 2nd Brigade, 101st Division, was to leave by February.
On Wednesday, however, the military announced the 2nd Brigade will instead return to its Fort Campbell, Ky., home base this month, after serving for 13 months, rather than the expected 15.
The unit served in northwest Baghdad, where violence has plunged, including a 50 percent decline in overall attacks in the area and a more than 90 percent drop in murders.
That will still leave more than 145,000 troops in Iraq, so it's only a down payment on meeting President-elect Barack Obama's goal of getting all combat brigades out of the country by the end of 2010, reports CBS News security correspondent David Martin.
The U.S. has to get down to just eight brigades in Iraq if it wants to build up its forces in Afghanistan, which Obama has said he will do, and at the same time give troops more time at home, reports Martin.
U.S. forces have also seen a dramatic decline in troop fatalities, with deaths falling to their second lowest monthly level in October. There were 14 U.S. troops killed last month, including seven lost in combat. That total was one more than the 13 deaths in July - the lowest monthly level of the war.
President Bush announced in September that the military would go from 15 to 14 combat brigade in Iraq some time in January - following recommendations from Gen. David Petraeus, then his top Iraq commander.
The decision sparked sharp criticism from Congress members who wanted Petraeus to recommend a swifter and larger drawdown in Iraq. And the plan appeared to push decisions for any more aggressive troop cutbacks to the next administration.
They complained that it made it more difficult to divert additional forces to Afghanistan, where commanders have repeatedly asked for thousands more troops.
At the time, however, Defense Secretary Robert Gates urged a cautious approach in Iraq, saying commanders did not yet believe the security gains were "enduring," and that there was the potential for reversals in the future.
More recently, however, Gates and other officials have talked more insistently about the need to boost troop levels in Afghanistan, noting that the increase cannot take place until more forces come home from Iraq.
Despite the overall drop in violence, nine Iraqis died in three separate bomb attacks that also injured two American soldiers.
Iraqi police reported a suicide bomber rammed his car into a police patrol on the road to Baghdad's airport Wednesday, killing six people and wounding 12 others.
Police said three officers were among those killed in the attack, while four policemen were wounded.
The heavily secured highway leading from central Baghdad to the capital's airport was once among the most dangerous stretches in Iraq. Insurgents staged almost daily attacks with roadside bombs and machine guns on U.S military convoys and civilian vehicles traveling to and from downtown Baghdad.
But security has improved markedly on the highway in the past 18 months since authorities blocked off side streets feeding onto the road put up blast walls along the highway.
Also Wednesday, two U.S. soldiers were wounded in a roadside bomb attack near the town of Karmah west of Baghdad as they responded to reports of a bomb in the area, the U.S. military said. Two Iraqis were killed, while an Iraqi interpreter, two Iraqi Army soldiers and 11 civilians were wounded in the bombing.
An Iraqi security official said the U.S. troops were injured as they rushed to the site of an earlier roadside bomb attack that killed a prominent leader of the local Awakening Council, the term for mostly Sunni groups that have joined forces with the Americans against al Qaeda in Iraq.
Elsewhere, one policeman died and three more were wounded when their patrol hit a roadside bomb in Amarah, 200 miles southeast of Baghdad, police said.
Wednesday's violence follows a series of bombings in Baghdad this week that have killed more than 30 people, and underscores that insurgents still pose a threat.
Meanwhile, the U.S. military said an American soldier died of non-combat related causes.
It was the first death reported since Oct. 29 among the 151,000-strong American military force in Iraq, and brought to at least 4,191 the number of U.S. military members who have died in the Iraq war since it began in March 2003, according to an Associated Press count.
U.S. officials say attacks in the Iraqi capital are averaging about four a day - down nearly 90 percent from levels of late 2006, when Shiite-Sunni fighting was at its high point and just before the U.S. troop surge that helped bring down violence in the capital. But U.S. commanders warn the security gains are reversible.