With the recent announcement that Australia will allow its female soldiers to serve in all combat roles, including the special forces and infantry, the United States government is once again confronted with an age-old question: Why are American women still denied the chance to serve their country equally on the basis of their sex?

American women now make up 14 percent of our armed forces and, as of 2008, there were 57 female generals or admirals on active duty, including six with three-star rank and one who had achieved four stars. More than 220,000 women have served in Iraq and Afghanistan, and more than 100 have been killed and thousands wounded. While American women can be assigned to most units in the military, they can only be attached to those engaged in ground combat. And the wars in Iraq and Afghanistan have shown that the difference between being assigned to a ground combat unit or attached to the unit — a practice used to circumvent the prohibition on women in combat — is a distinction without a difference.

In March, the congressionally mandated Military Leadership Diversity Commission released its recommendations for incorporating diversity into military leadership for the 21st century. The members of the commission included senior servicewomen and men from all branches of the armed forces who served in major armed conflicts ranging from World War II to Iraq and Afghanistan. One of its recommendations for assuring readiness through a diverse military force was to eliminate all combat exclusion policies for women in the armed forces, "to create a level playing field for all qualified servicemembers." Should the armed forces heed this recommendation, they would open more than 200,000 more military positions to women.

But this policy should not only end because it is fundamentally unfair to servicewomen. In addition, we must realize that our own military readiness is compromised when we prevent a full 14 percent of our forces from even being considered for some combat positions. We should be seeking to enlist as many service members as possible, rather than limiting our options so severely by restricting some combat service based on gender. Just as racial integration and the repeal of "Don't Ask, Don't Tell" strengthened our military readiness by removing barriers to service based on skill alone, allowing women to serve in all combat roles would give our armed forces a broader talent base to draw from and permit women to compete for advancement on a level playing field.

Opponents claim that women are not as physically strong as men and that this generalized scientific claim justifies excluding women from infantry and special forces units. But as U.S. Air Force Col. Martha McSally notes, this argument "is both over- and under-inclusive; many women have the physical strength to engage in ground combat while many men do not." Furthermore, men in the military do not undergo tests of physical strength before assignment to ground combat positions. Although it is likely true that not every woman can fulfill every physical demand of serving in combat, neither can every single man. Excluding all women because of a gender-based stereotype about physical strength ignores the fact that many women are indeed qualified to serve in all aspects of our military forces.

In announcing the defense policy change that will bring Australia in line with Canada, Israel and New Zealand's gender-neutral approach to combat assignments, Defense Minister Stephen Smith said, "In the future, your role in the defense force will be determined on your ability, not on the basis of your sex." This merit-based message resonates with both men and women in the armed forces, and we should honor them by embracing it in the United States.

Lawrence J. Korb is a senior fellow in national security at the Center for American Progress. His email is lkorb@americanprogress.org. Lucy Panza is a research associate at the center.