IT CERTAINLY must have been easier for the military -- and for the Foreign Service and many national corporations too -- back in the days when wives could be counted upon to devote full time and attention to the demands of husbands' employers. Packed up with the rest of the gear and shipped around from pillar to post, these women were in many cases treated like a valuable accessory, an unpaid extra who was assigned all kinds of tasks to be performed for the benefit of the company or the service. To make matters worse, a wife's performance in these tasks was often taken into account in determining her husband's career progress.

We thought those days were over -- but we were wrong. Two Air Force wives have recently complained about policies at Grissom Air Force Base in Indiana, and when these complaints became public, investigators found that their problem was not unique. These women held full-time civilian jobs, and in each case their husbands, midcareer officers in the Air Force, had been told that they would not be promoted unless their wives quit their jobs. Nothing subtle here. The commanding officer stated his terms as if he was not asking anything out of the ordinary. There's plenty of work to keep these women busy right here on the base, he said, and they're expected to volunteer to do it.

The predictable and justified protests -- is the Air Force caught in some kind of a time warp? -- from those familiar with the realities of women's rights, economic necessities and family relationships in the America of 1987, resulted in an Air Force investigation, a congressional inquiry and, this week, a new order from the Department of Defense. Secretary Caspar Weinberger announced that from now on the department will not interfere in any spouse's decision to work, to stay at home or to volunteer. That's a good ruling.

The point is not that all service wives want to work outside the home or that great numbers of them do not do extremely valuable volunteer community service on their own time. What was wrong here was the assumption on the part of their husbands' employer that it could command service from a spouse and forbid paid employment. A service wife doesn't abandon her individuality, her talents, her education and her ambition when her husband enlists. The difficulties and constant transfers of military life make it hard enough for such women to find work and develop their skills at it. At least now those who do hold jobs won't have to face an added hassle from the brass.