WASHINGTON – The Pentagon has moved to lift a decades-old policy that prohibits women from serving aboard Navy submarines, part of a gradual reconsideration of women’s roles in a military fighting two wars whose front lines can be anywhere.

At issue is the end of a policy that kept women from serving aboard the last type of ship off-limits to them.

The thinking was that the close quarters aboard subs would make coed service difficult to manage.

Defense Secretary Robert Gates notified Congress in a letter signed Friday that the Navy intends to repeal the ban on women sailors on subs.

Congress has 30 days to weigh in.

”He supports the Navy’s efforts to change their policy,” Pentagon press secretary Geoff Morrell said Tuesday.

A defense official told The Associated Press that numerous physical changes to submarines would have to be made, but that cadets who graduate from the Naval Academy this year could be among the first Navy women to take submarine posts.

The change was first reported by ABC News.

The official spoke on condition of anonymity because Congress has not yet had a chance to consider the Navy’s recommendations.

The Navy’s plan would phase in women’s service, beginning with officers aboard the larger subs that are easier to retrofit for coed quarters. Women would never serve solo.