Most of America's closest allies opted years ago to allow gays to serve openly in their militaries. As U.S. policymakers wrestle with the issue, there's sharp disagreement over whether those allies' experiences are relevant to the debate.
More than 25 countries let gays serve openly, including Israel's battle-tested forces and nearly every NATO military except Turkey and the U.S. In each case, there have been too few problems to prompt any high-level talk of abandoning the policy.
Is that track record evidence that the U.S. could and should follow suit? Or is America's military so different, in terms of its size, culture and global mission, that foreign examples are beside the point?
Among those pressing the case for irrelevance is Tony Perkins, a former Marine who is president of the conservative Family Research Council.
"The European culture is more permissive than ours," he said. "And no other military does the work that ours does. When you're looking at a military that has the burden we carry, we can't afford to get this wrong."
Despite such warnings, the U.S. now seems closer than ever to following its allies' examples. A federal judge has ruled the "don't ask, don't tell" policy unconstitutional, and the Obama administration — even while appealing that ruling — wants Congress to repeal the 17-year-old policy that in effect makes gay and lesbian service members stay in the closet to avoid discharge.
The Palm Center, a think-tank at the University of California, Santa Barbara, that supports repeal of "don't ask, don't tell," acknowledges that the U.S. military differs in many ways from its allies, but says their experiences with gays are relevant.
"The question is not how similar our missions or culture are to those of other nations but whether the United States is any less capable than other nations of integrating gays into its military," the center said in a recent report.
The collective experience of those countries "shows that if the U.S. were to lift its ban, American military performance would not decline," the center said.
To some conservatives, the NATO allies are flawed role models.
"Once a military force puts liberalization above military effectiveness, hallmarks of 'success' only relate to social goals," argues Elaine Donnelly, president of the Center for Military Readiness. "Our politically correct, socially liberal allies ... should be following the lead of the United States armed forces — not the other way around."
Donnelly notes that the countries still barring gays from their militaries include America's Muslim allies and potential rivals such as North Korea and Iran.
Bob Maginnis, a retired Marine colonel who's a national security analyst with the Family Research Council, says U.S. commanders would do their best to comply if ordered to let gays to serve openly. But he argues that step would be risky because of differences between the U.S. and its allies.
One difference, he contends, is a more active and litigious gay-rights movement in the U.S. — ready to place political and legal pressure on the military "no matter the consequences for combat effectiveness."
Maginnis also says the U.S. military, in contrast to its NATO allies, has large portion of personnel from conservative religious backgrounds who might object to serving with gays in what he terms "forced intimate situations."
"We have an overstretched volunteer force, and a lot of people are staying in just because the economy is bad," Maginnis said. "You add an additional couple of straws (by repealing "don't ask") and you're going to chase out a lot of people we can't afford to lose."
Some gays who have served in the military reject those arguments.
Jonathan Hopkins, a West Point graduate who served as an infantry officer in Iraq and Afghanistan, contended that U.S. service members, on the whole, are less hostile to gays than soldiers from other nations.
"It's the generals who aren't ready for" repeal of "don't ask, don't tell," he said.
Alex Nicholson, who was ousted from the Army nine years ago under "don't ask, don't tell," now heads Servicemembers United, a national organization of gay and lesbian troops and veterans.
Though he was discharged, he says many gays and lesbians currently in the ranks are "out" to some of their peers and commanders, and "the problems that are hypothesized do not materialize."
"The generation going into the military today is much more accepting of people different from them," Nicholson said. "They want to blow things up. They want to get away from home. ... It's ridiculous to try to paint them as churchgoing religious zealots."
David Segal, a University of Maryland sociologist who has studied military personnel policies, says the U.S. military is unique in its use of expeditionary forces to fight far-flung, long-lasting wars — yet he believes the experiences of U.S. allies in allowing gays to serve openly are instructive.
"Many of the nations that lifted their bans heard the same arguments," he said. "They all expected it would undermine unit cohesion, hurt recruitment and retention. ... None of that happened."
Some of them did encounter complications related to benefits and housing for same-sex couples, said Segal, who commended the Defense Department for examining these issues as part of an ongoing review.
"I do not anticipate it being perfect," Segal said.
"Our military resisted racial integration, it resisted gender integration," he said. "In both cases, the military kicked and screamed and said it would undermine our effectiveness. Once the decision was made, they saluted and followed in line."
Nicholson, of Servicemembers United, disagrees with all the arguments against allowing gays to serve openly, yet says he understands why some conservatives are waging such a vigorous campaign to prevent that.
"The military is such a large and fundamental institution in American society," he said. "There's a fear on the far right that once you stop using it as a tool to discriminate, it will be the domino that really accelerates the fall of the rest of the dominos."