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.