That's one of several changes in the military's law governing the service of gay troops that Gates and Adm. Michael Mullen, chairman of the Joint Chiefs of Staff, announced Thursday.
Although Gates said last month that he was ordering a study of the law, his decision Thursday pushed changes in the policy that go into effect immediately.
Supporters of scrapping the law applauded Gates' move, saying it would limit abuse under the policy and lead to its repeal. "These changes are by no means a substitute for full legislative repeal of the law this year, but they are certainly a good start," said Alexander Nicholson, a former U.S. Army interrogator who was discharged under the law and heads Servicemembers United, an interest group favoring repeal.
Co-sponsors of a Senate bill that would repeal the law commended the changes. "(It) is an important step on the path to a complete repeal," says Sen. Joe Lieberman, I-Conn., the bill's lead author. "This shows that our military can implement policies to end discrimination on the basis of sexual orientation while preserving our highest military standards."
Critics of changing the law, such as Sen. Saxby Chambliss, R-Ga., said Gates should wait for the results of the study and then decide what to do. "I'm a little bit surprised that he would take this kind of action," Chambliss said.
The changes are likely to create confusion and delay in discharge proceedings initiated under the law, says Elaine Donnelly, president of the Center for Military Readiness, which has advocated for keeping the policy in place.
"These changes will allow us to execute the law in a fair and more appropriate manner," Gates said. They "provide a greater measure of common sense and common decency to a process for handling what are difficult and complex issues for all involved."
Known as "don't ask, don't tell," the law allows openly gay men and lesbians to serve in the military but limits attempts to reveal their sexuality if they do not engage in improper behavior.
The changes in policy announced by Gates toughen the requirement for what constitutes credible evidence and demand special scrutiny of third parties who may be motivated to cause harm to a servicemember.
The guidelines ban certain categories of evidence such as information provided to lawyers, clergy and psychotherapists and to doctors providing medical treatment. The rules prohibit evidence about sexual orientation or conduct obtained during a security clearance investigation.
No bill to change the law has moved out of House or Senate committees. Lieberman's bill has 25 co-sponsors, all Democrats. A House bill introduced last year has 191 co-sponsors, including two Republicans, Ileana Ros-Lehtinen of Florida and Anh "Joseph" Cao of Louisiana.