About 300 US soldiers who recently returned home to Alaska after a year in Iraq have now been ordered back after their unit's deployment was extended.
The 172nd Brigade has been operating in northern Iraq
A further 300 soldiers - all of whom are with the 172nd Stryker Brigade - were in Kuwait en route home when they were recalled.
The 3,900-strong brigade was recently ordered to serve four more months.
They will be used to bolster security in Baghdad in a bid to halt rising sectarian violence in the country.
Maj General Charles Jacoby, head of US armed forces in Alaska, said he recognised that the decision would be a "huge disappointment" to the soldiers and their families.
"From a tactical and military standpoint, this makes all the sense in the world," he said. "The brigade needs these soldiers back."
The majority of the brigade were still in Iraq when the order to extend their deployment by four months was made by US Defence Secretary Donald Rumsfeld, but 378 had returned home.
Of those, 301 are now set to be sent back to Iraq in the next week. The remainder will not have to go back to Iraq.
All those who had arrived in Kuwait have now been sent back to Iraq, the army said.
Mary Cheney, wife of Staff Sgt Anthony Cheney and who had their fourth child a few weeks ago, said she was disappointed but philosophical about the news.
"Am I happy about him being gone? No. But I accept what he's doing," she said.
The army has sent a team of personnel and pay experts to Alaska to help soldiers sort out the upheaval caused by the decision to send them back, the Associated Press news reported.
Soldiers who serve longer than one year in Iraq are entitled to an extra $1,000 (£528) a month.
The 172nd Brigade has been operating in the Mosul area of northern Iraq, but is being moved to Baghdad as part of a major effort to stem the escalating violence there.