A federal judge’s ruling last month that the exclusion of women from Selective Service registration is unconstitutional has returned an age-old debate to the forefront: Does making the military more inclusive threaten military preparedness?

Critics have long alleged that integrating formerly excluded groups into the military advances social equality at the expense of military efficiency. This basic claim has been used repeatedly throughout U.S. history to oppose women, as well as African Americans and LGBTQ Americans, serving in the military, never mind compulsory service.

But in each of these cases, the fundamental premise behind the charge has been 100 percent false. Drafting women cannot turn the military into a social experiment, because the military has always been a social experiment. The inseparable nature between national defense and domestic social concerns ensures that who serves will always reflect social judgments and values that go far beyond military necessity.

Each time the military has used a conscripted force, it has engaged in social engineering. No military draft has ever required universal service. That is why it is called Selective Service; the draft selects those who, by virtue of their sex, age, physical and mental abilities, educational background and work skills, will best meet the military’s needs. Those deemed more valuable to the home front have been granted exemptions and exclusions. In many cases, those exemptions and exclusions hampered military efficiency for the sake of social concerns.

During the Civil War, both the Union and the Confederacy used conscription to preserve the social and racial order by allowing the wealthiest members of society to buy their way out of service. Wealthy men could pay a flat fee or offer a substitute in lieu of service. The Confederacy also exempted one white man on a plantation for every 20 slaves in an attempt to stave off potential slave revolts. These exemptions did little to bolster either side’s military forces. Instead, they led poor men to allege, not for the last time, that they were fighting a rich man’s war.

Conscription was a social laboratory again during both world wars. The Selective Service Acts excluded farmers, steelworkers and cod fishermen, to name but a few examples, not because they would not make good infantrymen but because their labor was deemed more essential to the home front than to the military. Mostly white local draft boards handed out the exemptions, though, and their racial, ethnic and class biases created a drafted force that was overrepresented by poor men of all races.

The impact of biases and non-military factors on the composition of the military force is especially clear when considering race. A day after the attack at Pearl Harbor, to keep African Americans out of the military, one Army adjutant general insisted that “the Army is not a sociological laboratory; to be effective it must be organized and trained according to the principles which will insure success.” This push failed, but the armed forces wasted a lot of money and resources supporting a segregated force that might have been better spent on the war effort.

After only a brief reprieve at the end of World War II, the draft was quickly reinstated, thanks to the nascent Cold War. But even after Harry Truman integrated the military racially, the Selective Service Administration engineered a socially stratified force to fight in Korea and Vietnam by granting college deferments. Scientists and engineers, they argued, would better serve national defense working in the civilian sector than in the military. It didn’t hurt that the educated were also the most well-connected in society.

Opponents resurrected the social-laboratory argument in the 1990s to oppose the open service of gay men and lesbians. They succeeded in forcing President Bill Clinton to renege on a campaign pledge and agree to the compromise “Don’t Ask, Don’t Tell” policy, which stood until 2011.

Gender has always been a factor in these decisions about who serves and who doesn’t. Married men and fathers have at times received exemptions, not because they did not make good soldiers but because, in the words of Sen. Joshua B. Lee (D-Okla.) in 1942, “the family is the fundamental unit of organized society.” Similarly, the Army engineered a nursing shortage crisis for itself in World War II in part because it refused to allow male nurses to serve in the nurse corps. Not because they were not good nurses, to be sure, but because Army commanders thought nursing to be inherently feminine work.

In fact, such assumptions about women’s innate natures outweighed the Army’s own evidence that women could effectively serve in combat roles. According to historian D’Ann Campbell, when Army experiments during World War II determined that mixed-sex anti-aircraft artillery units performed better than all-male units, Army staff suppressed the results because they did not believe the American public would accept women serving in those roles. It was not military efficiency that excluded the women from combat; it was concerns about public opinion.

Although the military has filled the ranks through a volunteer system since 1973, men have been required to register for with the Selective Service since 1980. When President Jimmy Carter reinstated registration, he proposed that women should register for noncombatant roles, but widespread fears about women being forced to serve in combat defeated his proposal before it even made it out of congressional committee. Again, it was politics, not military necessity, that shaped who might be part of the U.S. fighting force.

As the American public once again reconsiders who should register with the Selective Service, we should remember that we have debated this issue before. Requiring women to register will not make the military a social laboratory any more than it has always been one.

Who knows whether Selective Service will even continue? The congressionally created National Commission on Military, National and Public Service is midway through its study of whether the nation needs Selective Service at all. But whatever the eventual system, women must be included equally. We can’t exclude an entire class of Americans from the obligations and benefits of citizenship.

Our society requires it. So does our national defense. As one of our most famous soldiers, Dwight D. Eisenhower, said about women in 1948, “I am convinced that in another war they have got to be drafted just like men. I am convinced of that.”