WASHINGTON — Boy, you could see that one coming. It was a pivotal moment earlier this month when Joint Chiefs of Staff Chairman Mike Mullen and Defense Secretary Robert Gates backed repealing “don’t ask, don’t tell.” Pivotal, but not enough. I don’t spend a lot of time chatting up military officers, but enough to know that, just below the top-most ranks, there remains an enormous, if incomprehensible, amount of squeamishness about letting gay men and women serve openly in the military.

So it was disappointing but not surprising to see the chiefs of the Army and Air Force on Tuesday urging Congress to go slow on any change. “I do have serious concerns about the impact of repeal of the law on a force that is fully engaged in two wars and has been at war for eight and a half years,” Gen. George W. Casey Jr., the Army chief of staff, told the Senate Armed Services Committee. “We just don’t know the impacts on readiness and military effectiveness.”

Testifying before the House Armed Services Committee, Casey’s Air Force counterpart, Gen. Norton A. Schwartz, expressed his “strong conviction” that “this is not the time to perturb the force that is, at the moment, stretched by demands in Iraq and Afghanistan and elsewhere without careful deliberation.”

Perturb the force? Of course, the same arguments could be — in fact, they were — made about racial integration. It is particularly infuriating that the generals would invoke the wars in Iraq and Afghanistan as an excuse for not lifting the ban. If anything, “don’t ask, don’t tell” has been an impediment to the military during these operations. In an era of stop-loss recalls because forces have been stretched so thin, thousands of service members have been discharged because of their sexuality. According to some estimates, about 13,500 personnel have been kicked out since the policy was implemented during the Clinton administration. Nearly 800 of them had “critical skills.” More than 60 were Arabic speakers. As former Joint Chiefs Chairman John Shalikashvili wrote in a 2007 New York Times op-ed, “Our military has been stretched thin by our deployments in the Middle East, and we must welcome the service of any American who is willing and able to do the job.”

Do Casey and Schwartz really have so little faith in their troops that they think serving with people they probably already know are gay will impede their performance? Do they think U.S. personnel are less capable of adapting to this change than those in the 25 countries cited by the University of California’s Palm Center — including Britain, France, Canada, Germany, Israel, Argentina, Australia and South Africa — that allow gays to serve openly?

In the military, as elsewhere, this is, thankfully, a generational issue. Casey is 61, Schwartz just a few years younger. Younger officers, I suspect, are not much different from younger people outside the military: more comfortable with gay colleagues and friends. In the meantime, though, President Obama and congressional supporters of repealing “don’t ask, don’t tell” can’t let the generals intimidate them out of lifting the ban, or at the very least putting a moratorium on its enforcement. The scare-mongering worked 17 years ago. It’s even less convincing today.