Earlier this year, Mary Ann Gilleece, deputy undersecretary of defense for procurement, learned that her job was to be abolished in a reorganization. Miss Gilleece, who before her service in the Pentagon was counsel to the House Armed Services Committee, decided it might be time to try the private sector. She and an aide sent a letter of solicitation to 29 of the nation's large defense contractors in behalf of a venture they were contemplating called Procurement Strategy Corp. The 29 were companies over whose affairs Miss Gilleece then exercised considerable sway; it was her job as deputy undersecretary to help shape the Pentagon's procurement rules.

The letter inquired whether the companies might be interested in signing on with PSC, beginning this fall. Among other things, the contractors were told that the new consultancy would be able to "provide insights and assistance to build good working relationships with essential personnel, such as contract negotiators, auditors, quality assurance inspectors and program managers." PSC's clients would be able "to compete for government business with confidence and success," the prospectus promised. The price would be $30,000 per company per year for two years, plus expenses.

When reports of this planned undertaking appeared in the press -- a first partial report appeared in The Wall Street Journal in June -- the Pentagon went into its deepest defensive crouch. It was quickly said that before sending out her letter Miss Gilleece had consulted both the Pentagon's ethics officer and its general counsel; that she had not used government stationery; and that she had recused herself from any decisions affecting the companies contacted. How she had been able to function when thus recused was not made clear. At one point the Pentagon line was that "there are lots of other companies" from whose affairs she had not recused herself. At another, the line was that she rarely dealt with individual companies anyway, that "virtually none of her responsibilities concern or affect particular contractors."

In fact, it appears that most of her important work affected all contractors. Miss Gilleece in her time as deputy undersecretary was a powerful defender of the defense procurement process. She resisted a series of efforts by Congress to "reform" it -- to require that contractors provide the department with warranties, for example, or to certify that all their charges are allowable. "I believe that we are 99 and 44/100s percent pure," she once testified.

Miss Gilleece has now apparently abandoned her plan to set up PSC, and the Pentagon, if ever it had one, has abandoned any thought of admonishing her. James Wade, the new assistansecretary in charge of procurement, did acknowledge at a news conference that "one could question -- you know, in the sense of perception -- whether that was a wise thing to do as a member of the government team. I don't think it was the best thing to do." But "technically she was fine," he said, and Pentagon spokesman Fred Hoffman said investigators "found nothing improper in what she did, or illegal."

It won't wash. Whenever a new procurement debacle occurs and Congress moves (again) to reform the rules, the Pentagon complains that the rules already on the books are choking it. Don't hamstring us further, the officials in charge beg. Trust us.

That is not an idle argument. Congress is doubtless a clumsy writer of procurement rules, as many of its own best members would freely admit. But the public trust the Pentagon seeks must be earned, and in the crudities of the Gilleece case it seems to us it has instead been betrayed.