A Navy stenographer assigned to the National Security Council during the Nixon administration "stole documents from just about every individual that he came into contact with on the NSC," according to newly declassified White House documents.

The two-dozen pages of memoranda, transcripts and notes -- once among the most sensitive and privileged documents in the Executive Branch -- shed important new details on a unique crisis in American history: when investigators working for President Richard Nixon discovered that the Joint Chiefs of Staff, using the stenographer as their agent, actively spied on the civilian command during the Vietnam War.

The episode became known as "the Moorer-Radford affair," after the chairman of the Joint Chiefs at the time, the late Admiral Thomas H. Moorer, and the stenographer involved, Navy Yeoman Charles Radford. The details first surfaced in early 1974 as part of the Watergate revelations, but remained obscure until historians in the 1990s and this decade began fleshing out the episode.

The affair represented an important instance in which President Nixon, who resigned in 1974 amid wide-ranging allegations that he and his subordinates abused the powers of the presidency, was himself the victim of internal espionage. In adding to what has already become known about the episode, the latest documents show how the president and his aides struggled to "get a handle on" the young Navy man at the center of the intrigue and contain the damage caused by the scandal.

A trained stenographer, Radford was in his late twenties when he was assigned to the NSC staff of Henry Kissinger during Nixon's first term. The yeoman worked out of the Executive Office Building under two admirals, Rembrandt Robinson and Robert O. Welander, who served as formal liaison between the Joint Chiefs of Staff and the NSC. As Radford later described his work -- in polygraph tests, sworn testimony, and interviews with historians and journalists -- he spent 13 months illegally obtaining NSC documents and turning them over to his superiors, with the understanding that the two admirals were, in turn, funneling the materials to the chairman of the Joint Chiefs and other top uniformed commanders. Radford's espionage took many forms: making extra photocopies of documents entrusted to him as courier; retrieving crumpled drafts from "burn bags"; even brazenly rifling through Kissinger's briefcase while the national security adviser slept on an overseas flight.

Nixon's team of in-house investigators -- informally known as "The Plumbers," since their primary mission was to stop leaks of classified materials to the news media -- discovered Radford's covert activity in December 1971, during their probe into a sensational series of stories published by the syndicated newspaper columnist Jack Anderson. A thorn in Nixon's side since the 1950s, Anderson had obtained highly classified minutes of NSC meetings about the India-Pakistan War then roiling South Asia, and published excerpts from the documents just days after they were typed up. In addition to disclosing sensitive information about the movement of a carrier task force in the Bay of Bengal, the series showed the Nixon administration had deceived the public about its true aim of supporting Pakistan in the conflict, and later won Anderson the Pulitzer Prize.

Inside the Nixon administration, however, where officials were still reeling from other high-profile leaks -- like The New York Times' publication of the Pentagon Papers in June, and the paper's disclosure of key details in the United States' nuclear arms talks with the Soviet Union -- the Anderson columns inspired outrage. A joint Plumbers-Defense Department investigation quickly zeroed in on Radford, who was known to have had contacts with Anderson, a fellow Mormon, and to have enjoyed access to virtually all of the documents the columnist had published.

Under intensive polygraph testing in late 1971, Radford denied having leaked the India-Pakistan documents to the columnist. (Anderson died in 2005 without ever disclosing who had been his source, but he told author Len Colodny in November 1986: "You don't get those kind of secrets from enlisted men. You only get them from generals and admirals.") However, the young stenographer did eventually break down and tearfully admit to Nixon's investigators that he had been stealing NSC documents and routing them to his Pentagon superiors. Radford later estimated he had stolen 5,000 documents within a 13-month period.

Radford's stunning admission presented President Nixon with an unprecedented challenge to his wartime authority by the military's top uniformed commanders -- and with a delicate political situation. According to White House tapes released by the National Archives in 2000, and first published by this author in the Atlantic Monthly magazine in April 2002, Nixon wanted to prosecute Moorer for espionage but was convinced by Attorney General John N. Mitchell that the ensuing controversy would imperil Nixon's secret foreign policy initiatives and do grave damage to the armed forces. Instead, Mitchell was sent to confront Moorer and tell him, as Mitchell put it, that "this ball game's over with"; Radford's home was wiretapped; and he and his immediate supervisor were eventually transferred to remote posts. But the president and his men had no doubt about the ultimate consumers of Radford's espionage fruits.

"(T)he whole concept of having this yeoman get into this affair and start to get this stuff back to the Joint Chiefs of Staff," Mitchell told Nixon in one tape-recorded conversation, "is just like coming in and robbing your desk."

The matter remained buried from December 1971 until January 1974, when sketchy newspaper reports about the episode led to brief and inconclusive hearings by the Senate Armed Services Committee. As the Watergate scandal mushroomed and Nixon's political fortunes worsened, he and his advisers gave thought to exposing the Moorer-Radford affair, as an example of legitimate national security work undertaken by the Plumbers, but again decided that disclosure of the Joint Chiefs' spying would stain the military's honor.

"Admiral Moorer," Nixon told an aide in May 1973, "I could have screwed him on that and been a big hero, you know. I could have screwed the whole Pentagon about that damn thing ... Why didn't I do it? Because I thought more of the services."

(Moorer, who died in 2004, denied involvement in any improper or illegal activity, but did acknowledge, in an interview with CBS News in February 1974, that he perhaps should have been more alert in tracing down the precise origin of these papers he received.)

The new materials on the case -- among 90,000 pages of documents and 200 hours of Nixon tape recordings declassified by the National Archives and made available to researchers earlier this month -- show Kissinger enjoyed a greater role in the Moorer-Radford investigation than was previously known. The materials also give new insights into how Nixon and his top aide in charge of the Plumbers, John D. Ehrlichman, grappled with the complex problems the case posed.

On Dec. 21, 1971, the day Ehrlichman and Mitchell showed up in the Oval Office shortly after 6 p.m. to break the news about the Joint Chiefs' involvement to the commander-in-chief, Kissinger wrote to Radford's superior, Admiral Welander, to urge him to "cooperate completely" with the Plumbers' investigation.

"(T)here is no aspect of our relationship, regardless of how confidential, that you should not feel free to share with (Ehrlichman)," Kissinger wrote. (In his memoirs, Kissinger alluded to the Moorer-Radford affair in only the briefest and vaguest of terms. Transcripts of his private telephone conversations released years later, however, showed that the national security adviser worried about "these people spying on me" and added: "I could never tell whether this was super-bureaucratic gamesmanship, or something a little more sinister. My feeling is that ... it may have started as bureaucratic gamesmanship and it got out of control.")

Ehrlichman's aide, David R. Young, led the Plumbers' investigation into Radford and his activities. The newly declassified documents show Young and Ehrlichman wrestling with how best to extract information from Radford without pressing him too hard.

"(Radford) is presently at his residence and can be called in on two hours' notice," Young wrote to Ehrlichman on Dec. 21. "Defense does not want to push him right now for fear that he may decide to get a lawyer."

The following day, as Ehrlichman prepared to conduct a taped debriefing of Welander, Radford's immediate supervisor and the key link between the yeoman and the Joint Chiefs, Young delivered Ehrlichman a detailed memorandum listing all the relevant subjects and areas to be explored. "Radford has admitted that he stole documents from just about every individual that he came into contact with on the NSC," wrote Young.

He encouraged Ehrlichman to mention to Admiral Robinson that the young stenographer-spy had already told investigators that he believed the material he had been stealing was destined to go to "your superiors," meaning the Joint Chiefs. Young also urged Ehrlichman to determine the extent to which Kissinger's top NSC deputy -- Alexander Haig, who had personally selected Radford to accompany Kissinger on his overseas trips, and who later went on to become secretary of state in the Reagan administration -- was "aware of Radford's activities."

Nixon and his men eventually concluded that Haig had been complicit in the Pentagon spying, but opted not to take any action against him.

However as late as Jan. 18, 1972, by which time the president and attorney general had effectively buried the scandal, Young was still advising Ehrlichman on the various federal statutes that could be used to put Jack Anderson behind bars, in a memorandum entitled: "BASIS FOR PROSECUTION OF OUR FAVORITE COLUMNIST."

"For obvious political reasons," Young wrote at the dawn of a presidential election year, "I am not advocating the above at this time, but for background ... (Anderson) could be fined up to $10,000 or imprisoned up to ten years."

Finally, the new materials provide further details on an avenue of investigation in the case that President Nixon wanted the Plumbers to pursue, but which they ultimately did not: to tie Radford to columnist Anderson through an alleged homosexual relationship between the two Mormons, both of whom were married with children. The newly declassified documents include a previously unpublished transcript of a telephone call between Ehrlichman and Defense Secretary Melvin Laird that Ehrlichman, having caught the Nixon White House fever, surreptitiously recorded.

"I don't think we should go on the homosexuality thing," Laird told Ehrlichman on Dec. 23. "Why not?" Ehrlichman asked. "I don't think we have any basis to even draw up a series of questions (about it)," Laird replied. "(T)here's nothing to indicate homosexuality and we have to notify (Radford) ahead of the (polygraph) exam as to the topics to be covered. ... If (Radford) decides not to take the test and then goes out and tells the press that that's what we're running here, I think we just get in a hell of a lot of -- we blow the lid."

Ehrlichman told Laird that he would revisit the idea with Nixon. "(T)he president has instructed me to go on this," said Ehrlichman. "It was his idea. And here's why: Because there is no apparent motive for this fellow (Radford) turning these papers over to Anderson."

Laird, a former congressman from Wisconsin with long experience on the House defense appropriations committee, took the opportunity to remind the White House that he had advised the commander-in-chief, long before the Moorer-Radford affair, to close down the JCS-NSC liaison office to which Radford had been attached.

"When I first came over here (in January 1969), I suggested that we shut off this channel," Laird told Ehrlichman in the newly declassified transcript. "It gave the chiefs a position where they could go to Congress on various things, on things that they shouldn't have known about within the administration, and could get information to us on the Hill from time to time. I think the president will recall on several times I told him various bits of information and I got that information through that particular channel. ... I felt that should be shut off."

James Rosen is a FOX News Washington correspondent and author of "The Strong Man: John Mitchell and the Secrets of Watergate" (Doubleday).