The U.S. Armed Forces are on the verge of allowing women to serve in ground combat units beneath the brigade level. Women already are serving and dying (over 110 in Iraq and Afghanistan) in many hazardous military jobs. They serve as fighter, bomber and helicopters pilots; and they serve in ground combat-support units that put them in harm's way. Why shouldn’t they serve in front-line combat units?

The Military Leadership Diversity Commission, established by Congress two years ago, is expected to send to Congress in March a report recommending doing away with current prohibitions on women in combat. The U.S. Army is working on its own report; and it appears that increasingly senior military leaders are ready to accept a change of policy.

People who oppose women in combat provide various reasons why they believe it’s not a good idea. The two most often heard are that women aren’t physically strong enough; the average load an infantry warrior carries in Iraq and Afghanistan is 120 pounds. And, we shouldn’t subject women to the brutalities of combat where they are more likely to be killed or captured. The thought of their captors raping and otherwise abusing American female POWs is abhorrent.

Proponents of women serving in combat units—recent polls show that a slim majority of Americans support it—respond that nothing should stand in the way of full equality for women in the military. Women can’t compete for promotion to the highest ranks if they can’t demonstrate combat leadership and experience. Today’s U.S. military is an all-volunteer force, they emphasize, and it should allow women who volunteer for combat units and meet the requirements to serve in them. They will also argue that there is no bastion of male dominance that hasn’t benefited when women have full equality, and that includes the military.

The debate over women in combat is as old as civilization. Women have fought and died beside men for thousands of years. History is replete with warrior women; but few civilizations have, as a matter of policy, recruited or impressed large numbers of woman into military service unless it was a matter of survival. That isn’t only because the rigors of hand-to-hand combat before the introduction of modern weapons required great strength and endurance. It’s also because civilizations weren’t willing to sacrifice woman of child-bearing age who insured the continuation of their society and culture. There were many reasons ancient conquering armies slaughtered men, women, and children or carted them away as slaves. One of them was to ensure the permanent defeat of a tribe or people by cutting its birth rate to zero.

Such considerations no longer apply in the modern world, but the idea of physical combat as a male-only profession has persisted. Currently, the only mixed ground-combat unit in the world is the volunteer Karkal Battalion in the Israeli Army. And although the tide of public opinion in the U.S. appears to have now tipped in favor of women in combat, it’s also in the context of volunteer service. I could not find a poll that asked the question, do you favor compulsory service for women in combat units?