IF YOU'D like to know what theories the courts are exploring to govern the military's policy on homosexuals, take a look at a case called Watkins v. United States Army, which was decided by the U.S. Court of Appeals for the Ninth Circuit 18 months ago. On Monday, the Supreme Court refused to hear an appeal in this case, so while the case sets no national precedent, the majority opinion stands. But concurring and dissenting opinions filed in the case are equally interesting, the latter because it sets out traditional legal thinking on this subject, and the former because it presents a powerful case for sweeping change.

Sgt. Perry Watkins is a homosexual. He disclosed that to the Army at the time he was drafted, but it was during the Vietnam War and according to the court, "the examining psychiatrist apparently did not believe {him}." A year later, in the course of a criminal investigation by the Army (no charges were ever brought against him), Sgt. Watkins signed an affidavit stating that he had been a homosexual since the age of 11. Four years after that, he was denied a security clearance (it was granted later) on grounds of homosexuality, but no steps were taken to remove him from the service. His performance record was extraordinary, and the court quotes numerous passages commending his ability, recommending promotions and stating that his homosexuality was well known but caused no problems and generated no complaints. He served for 14 years, but when his last tour expired in 1982 he was denied permission to reenlist.

A majority of the court, invoking the Common Law doctrine with the fetching name of "equitable estoppel," held that the Army's conduct and Sgt. Watkins's reliance on it to his own detriment barred the government from invoking the regulations against homosexuality at this point, a mere six years short of retirement. This certainly was the only fair thing to do as far as this plaintiff is concerned. Four dissenting judges would have deferred to the military's expertise in this area and allowed the Army to rely on its own regulations. But there was another forceful opinion in the case that goes beyond the majority's ruling. Two concurring judges found that the Army's treatment of homosexuals as a class violates the constitutional guarantee of equal protection and should be overturned. This view is still very much a minority opinion, but it is the position likely to be taken by more and more plaintiffs challenging this service policy in the years ahead.

The Supreme Court's action this week, refusing to disturb the narrow ruling in favor of Sgt. Watkins, comes less than two weeks after retired Justice Lewis Powell made a startling public comment about another case involving civil liberties and homosexuals. Justice Powell, in answer to a question, said that he regretted his decision in the 1986 case of Bowers v. Hardwick. That ruling, in which Justice Powell cast the deciding vote, upheld Georgia's sodomy statute. His statement, though obviously without any legal force, could be consequential in its way, and will no doubt be invoked when gay rights litigants bring this issue to the Supreme Court again.