In Mary McGrory's column last Sunday, the site of a meeting for a drafting session of CIA director William J. Casey's Iran-Contra testimony was incorrectly identified. The meeting was not in the office of then-White House counsel Peter J. Wallison. (Published 7/1/87)

DISPATCHING Charles J. Cooper to the White House to find out what had gone on in the Iranian arms deal was comparable to sending a child to a tough corner bar to shake out a brawl.

Attorney General Edwin Meese III nonetheless ordered young Cooper to do a little sleuthing -- he called it "legal analysis" -- in the shambles that attended the disclosure last Nov. 4 of the United States' brisk one-way missile traffic with Teheran.

Cooper, a graduate of the University of Alabama law school, has a turned-up nose, a trusting face and a blow-dried haircut. He found favor with his superiors in the Justice Department, and after a spell in the civil rights division was moved to the office of legal counsel. It is his job to provide advice to the attorney general, although it is hard to imagine Meese, with his mounting legal difficulties, turning to Cooper unless he was overcome by a sudden craving for turn-of-the-century phraseology or an unsuspecting mind.

Coooper speaks in a kind of Victorian copybook prose, ever seeking the elegant variation for the blunt. Here is his expurgated version of what Meese said when he was told of Oliver North's famous "smoking gun" memo about diversion of arms profits to the contras:

"He -- my recollection is that the attorney general said something analogous to 'Oh, darn'." During the inevitable explosion of laughter in the Senate Caucus Room, Cooper added that it was probably "more strenuous than that."

In his first few weeks of sleuthing -- he received his "heads up" from Meese on Nov. 7 -- Cooper wandered around having "little chats" with the legal counsel of the National Security Council, Cmdr. Paul Thompson, and National Security Adviser John Poindexter. He certainly didn't pry.

Thompson, he said earnestly, "was making clear to me that there was an effort, a very intense effort within the National Security Council by the people most knowledgeable, to gather those facts and to share them with me as soon as possible." Actually, of course, they were lined up at their computers to rewrite history.

In spite of himself, Cooper found out certain things, like the fact of the November 1985 arms shipment.

"I can't tell you what amount of time elapsed, but I did not tarry," Cooper said of his prompt report to the attorney general. Cooper's uneventful wait for the NSC chronology was punctuated by two events. One was Ronald Reagan's Nov. 19 press conference in which the president flatly denied that Israel had sent arms to Iran at our behest. Cooper sprang into unaccustomed action. He called Thompson. But let him tell it: "I didn't need really to articulate my concern and he told me that a correction would be forthcoming instanter {sic}."

The next day Cooper had an experience that would have shattered any but the most indestructible innocence. He attended Oliver North's school for lying.

Class convened in the office of White House Counsel Peter Wallison. The pupils were high-powered: Poindexter, CIA Director William J. Casey, Deputy Director Robert Gates and the attorney general.

The teacher at what committee counsel Pam Naughton gently dubbed "a drafting session" was North. The subject: testimony on the November 1985 arms sale that Casey was to give to the Senate Intelligence Committee the following day.

The students were given an insertion that was the focus of everybody's attention. Originally, Casey was scheduled to tell the committee that nobody in the CIA knew about the arms shipment. That was a pretty big lie, but North wanted to tell a bigger one.

North's revision: "No one in the U.S. government found out that our airline had hauled Hawks until January."

Cooper explained that North "wanted to eliminate the inference that someone in the U.S. government knew about this even if the CIA didn't."

Cooper had no problem with any of it. "I mean, they did not appear to me to have any personal knowledge of this matter," he assured the unbelieving committee.

The only reason Casey did not get his diploma from lying school the next day was that Abraham Sofaer, general counsel of the State Department, blew the whistle. He was trying to protect his principal, the secretary of state, who knew full well what was on the plane because he had been told by the national security adviser the year before. If the matter were not corrected, Sofaer told the bewildered Cooper, he was "almost certain" he would leave government.

Cooper turned out to be the single most valuable witness on the coverup that has come to the stand so far. He was a kind of innocent, uninvolved John Dean. He was living proof that even those who least want to know are bound to find out that lying in the Reagan White House was a way of life.

Mary McGrory is a Washington Post columnist.