The recent repeal of the "don't ask, don't tell" restriction on military service is an important advance both for national security and for civil rights. As President Obama said in heralding repeal, "It is time to recognize that sacrifice, valor and integrity are no more defined by sexual orientation than they are by race or gender, religion or creed."

But wait. In the military, the exercise of these values is still officially limited by gender. It's time to lift the remaining gender restrictions on military service, too.

In little-noticed action in December, both the Military Leadership Diversity Commission established by Congress in 2008 and the nearly 60-year-old Defense Advisory Committee on Women in the Services recommended just that. Both panels based their recommendations on findings that the current restrictions on women's military service are both difficult to apply and outmoded, given the nature of warfare today and the positive performance of military women in a variety of vital combat roles.

In the early 1990s, Congress lifted the last remaining statutory restrictions on women's military service, opening up combat aircraft and combat ships to women. In addition to complying with the new law, then-Secretary of Defense Les Aspin in 1994 expanded military policy even further, opening up tens of thousands of positions previously closed to women and ordering that only "direct ground combat" positions remain closed. He defined "direct ground combat" as "engaging an enemy on the ground with individual or crew-served weapons, while being exposed to hostile fire and to a high probability of direct physical contact with the hostile force's personnel... [It] takes place well forward on the battlefield while locating and closing with the enemy to defeat them by fire, maneuver, or shock effect."

Under the 1994 directive, the services are permitted to keep certain positions closed to women in limited circumstances beyond "direct ground combat." In the intervening years, however, the services have opened some of these positions to women as well, including submarine service in 2010. Moreover, although the 1994 directive does not permit women to be "assigned" to direct ground combat units, commanders in the field have discretion to "attach" women to such units. As several press reports have confirmed, many commanders in Iraq and Afghanistan are executing such attachments in order to best use their available talent. The media have reported that women have been included in field artillery units patrolling an extremely dangerous section of Baghdad, although they could not officially be assigned to those units. However, these "attachments" may not be noted in a service woman's record, making it hard for her to get proper credit for her combat-related service or to later get treatment for combat-related conditions such as PTSD.

Whatever may have been the basis for the direct ground combat rule, it is no longer warranted. As the conflicts in Iraq and Afghanistan demonstrate, defined fields of battle in which certain troops are "well forward" no longer exist. Every service member in these theaters is exposed to "hostile fire and to a high probability of direct physical contact with the hostile force's personnel." Moreover, as women have moved into combat positions, including through their "attachment" to ground combat units, they have repeatedly proved their mettle. As Admiral Mike Mullen, the chairman of the Joint Chiefs of Staff, said in November, "no matter how many doors we have opened for women in the military... there are still too many others yet closed... Today, women are... serving magnificently all over the world in all sorts of ways. More critically, in these wars of ours, they've served and sacrificed and led every bit as much and every bit as capably as any man out there. Well over 200,000 women have served in Iraq and Afghanistan, demonstrating tremendous resilience, adaptability and capacity for innovation."

In 2006, rejecting efforts to enshrine in statute a limited combat role for women, Congress required only that the secretary of defense provide 30 days notice of any change in current policy to both the House and Senate. As a matter of national security and civil rights, it's time for Secretary of Defense Robert Gates to give that notice, eliminating all restrictions on women's military service. Only then will, in President Obama's words, the "sacrifice, valor and integrity" of military service not be defined by gender.

Nancy Duff Campbell is Co-President of the National Women's Law Center and Vice-Chair of the Defense Advisory Committee on Women in the Services.