When American soldiers get off duty in Iraq, the men usually return to their quarters, the women to theirs. But staff sergeant Marvin Frazier gets to go back to a small trailer with two pushed-together single beds that he shares with his wife.

In a historic but little-noticed change in policy, the army is allowing scores of husband-and-wife soldiers to live and sleep together in the war zone - a move aimed at preserving marriages, boosting morale and perhaps bolstering re-enlistment rates at a time when the military is struggling to fill its ranks five years into the fighting.

Long-standing army rules barred soldiers of the opposite sex from sharing sleeping quarters in war zones. Even married troops lived only in all-male or all-female quarters and had no private living space. But in May 2006, army commanders in Iraq, with little fanfare, decided that it is in the military's interest to promote wedded bliss.