WASHINGTON — A military advisory commission is recommending that the Pentagon do away with a policy that bans women from serving in combat units, breathing new life into a long-simmering debate.

The call by a commission of current and retired military officers to let women be front-line fighters could set in motion another sea change in military culture as the armed forces, generations after racial barriers fell, grapples with the phasing out of the ban on gays serving openly.

The newest move is being recommended by the Military Leadership Diversity Commission, established by Congress two years ago. The panel was to send its proposals to Congress and President Barack Obama.

It is time "to create a level playing field for all qualified service members," the members said.

Opponents of putting women in combat question whether they have the necessary strength and stamina. They also have said the inclusion of women in infantry and other combat units might harm unit cohesion, a similar argument to that made regarding gays. And they warn Americans won’t tolerate large numbers of women coming home in body bags. Those arguments have held sway during previous attempts to lift the ban.

Congress recently stripped the "don’t ask, don’t tell" ban on gays serving openly, and the Navy changed its rules over the last year to allow women to serve on submarines for the first time. Women are barred from certain combat assignments in all the services but face the broadest restrictions in the Army and Marines.

Anu Bhagwati, a former Marine captain and executive director of the advocacy group Service Women’s Action Network, said the prohibition on women in combat "is archaic, it does not reflect the many sacrifices and contributions that women make in the military, and it ignores the reality of current war-fighting doctrine."

Although thousands of American women have served in the Iraq and Afghanistan wars and been exposed to great danger — 134 of them have been killed — they have been largely restricted to combat support jobs such as medics or logistical and transportation officers.

Defense policy prohibits women from being assigned to any unit smaller than a brigade whose primary mission is direct combat on the ground.

The new report says that keeping women out of combat posts prohibits them from serving in roughly 10 percent of Marine Corps and Army occupational specialties and thus is a barrier to advancement.

"The Armed Forces have not yet succeeded in developing leaders who are as diverse as the nation they serve," said the report. "Minorities and women still lag behind white men in terms of number of military leadership positions."

Women generally make up about 14 percent of the armed services. Of the roughly 2.2 million troops who have served in Iraq and Afghanistan, more than 255,000 have been women, said Pentagon spokeswoman Eileen Lainez.

Supporters of the change say women essentially have been in combat for years, even if they are nominally removed from it.

"It’s something whose time has come," said Lory Manning of the Women’s Research and Education Institute. She said ending the ban would be "a logical outcome of what women have been doing in Iraq and Afghanistan, where the Army and Marines have been essentially ducking the policy."

She said, for example, that military officials have employed terms of art to skirt the ban, for example "attaching" women to a combat unit instead of "assigning" them.

The new report says there has been little evidence that integrating women into previously closed units or military occupations has damaged cohesion or had other ill effects. It says a previous independent report suggested that women serving in combat in Iraq and Afghanistan "had a positive impact on mission accomplishment."

Defense leaders have said they see the change coming someday. For example, Defense Secretary Robert Gates said in September that he expects women to be let into special operations forces eventually, and in a careful, deliberate manner.

The advisory commission recommends a phased-in approach. The Army is doing its own internal study of women in combat as well.

Pentagon figures show that as of Jan. 3, 110 women had been killed in the war in Iraq compared with about 4,300 men. In the Afghanistan campaign, 24 women have been killed compared with more than 1,400 men.

Lainez said the department will review the recommendations when the report is delivered.

But regardless of what becomes of the policy, she noted that women will continue to be drawn into combat action, "situations for which they are fully trained and equipped to respond."