The U.S. military fired 11 servicemembers in January, though they did nothing wrong, Rep. Jim Moran, D-Va., revealed to me. Why? They were found to be gay.

These troops — specialists in intelligence, infantry, military police and health care — are the latest casualties of the "don't ask, don't tell" policy that President Obama has promised to end.

The White House has said it wants to consult with the Pentagon and study what effect ending the ban would have on the military. But we've seen this movie before: Every time the military has been consulted on this issue, it has trotted out the old "unit cohesion" argument, which asserts that openly gay servicemembers would weaken the military by hurting morale, recruitment, good order and discipline.

The problem is the unit cohesion argument has no basis in fact. And while plenty of research shows that openly gay service works, this evidence has routinely been ignored.

The military, it turns out, never had good reason to ban open gays from service. In researching a book on "don't ask, don't tell," I spoke over the past two years with senior military officers who were involved in the creation of the policy 16 years ago. Several admitted candidly that the gay ban was never rooted in research about what was good for the military, but was simply based on fear and prejudice.

To cool the raucous national debate on gay service early in his administration, President Clinton called a "timeout" and ordered two studies of the issue. One was conducted by RAND Corp., a think tank created by the military, which found in its 500-page report that sexual orientation was "not germane" to military service. But the Pentagon found those conclusions unacceptable. According to The New York Times, military officials never considered the report because the Joint Chiefs of Staff, headed by Gen. Colin Powell, had already decided to keep the ban.

Instead of heeding the RAND report, the current policy was essentially written by six admirals and generals who made up the second study group assigned by Clinton.

The first head of this group was Lt. Gen. Robert Alexander, who told me his team "didn't have any empirical data," so the conclusions it drew were purely "subjective." It was "very difficult to get an objective, rational review of this policy," he said. One group staffer, Vince Patton, tried to provide research to the flag officers in charge, but he said it was never even considered. According to Patton, the policy was created "behind closed doors" by people who were impervious to data, and who relied on fear and anti-gay stereotypes instead.

Rear Adm. John Hutson, who would become the judge advocate general of the Navy, was a participant in that service's talks about whether to lift the ban. Hutson told me the process was "based on nothing. It wasn't empirical, it wasn't studied, it was completely visceral, intuitive." He said that the policy came out of "our own prejudices and our own fears," and that it was a "moral passing of the buck."

These and other military officials have acknowledged what many have long suspected: The ban on openly gay service was not based on sound research because no research has ever shown that openly gay service hurts the military.

Let's hope that this time around, our military and political leaders consult the considerable research that now exists on this topic, which, like the RAND report, shows indisputably that military readiness and equal treatment are not at odds, but go hand in hand.

Nathaniel Frank, author of Unfriendly Fire: How the Gay Ban Undermines the Military and Weakens America, is senior research fellow at the Palm Center, University of California-Santa Barbara.