President Obama has brought welcome if belated attention to the nation’s unfair policy regarding gays in the military. “Don’t ask, don’t tell” was wrong when it was enacted 16 years ago, and it’s time for it to go.

In his State of the Union address last month, Mr. Obama pledged to scrap the prohibition against gays’ serving openly in the military, and he is receiving important new support.

Unlike in 1993, when “don’t ask, don’t tell” replaced an outright ban on gays in the service, public opinion now comfortably favors acceptance. And, in a historic development last week, the nation’s two top defense officials called for “don’t ask, don’t tell” to end. Speaking to the Senate Armed Services Committee, Defense Secretary Robert Gates and Mike Mullen, chairman of the Joint Chiefs of Staff, urged repealing the policy. Mr. Gates said the Pentagon is undertaking a year-long study of how to implement the change. More immediately, it will look into ways of relaxing the policy’s enforcement.

Early in his administration, former President Bill Clinton gave up an enormous amount of political capital trying to get the ban on gays in the military lifted. Colin Powell, then chairman of the Joint Chiefs of Staff, opposed him but supported “don’t ask, don’t tell,” which lets gay men and women serve as long as they do not disclose their sexual orientation. This dubious compromise has forced otherwise qualified men and women to lie about who they are. It has also kept many in a constant state of anxiety about whether they might be exposed. Thousands have been needlessly expelled since this misguided policy became law, and Mr. Powell now supports its repeal.

The arguments against gays in the military — that they would harm morale and undermine cohesion — were always flimsy and have been proved false by studies. Moreover, attitudes are changing. Younger heterosexual soldiers are far more tolerant of gays than those now heading for retirement.

Changing “don’t ask, don’t tell” requires an act of Congress. Technically, the president could sign an executive order mandating the change, but it would be effective only through the end of his presidency. Symbolically and practically, it is better for gays to secure this right legislatively. It is also generally better for the country when significant social change is approved by its elected representatives.

For years, one of the strongest voices in favor of letting gays serve openly was 1964 Republican presidential candidate Barry Goldwater. Fiercely conservative, he argued before its adoption that “don’t ask, don’t tell” was an unacceptable intrusion on Americans’ private lives. “Lifting the ban on gays in the military isn’t exactly nothing, but it’s pretty damned close,” he wrote. The sky will not fall if Congress, at long last, ends this insult to gay men and women.