WITHOUT G. GORDON LIDDY, the Watergate scandal would never have happened. He dreamed up and managed the most adventurous, illegal and bungled schemes of the Nixon Administration's covert domestic operations. It would not be too much to say that he was both the Rodgers and the Hammerstein of Watergate: music and lyrics by Gordon Liddy. Dozens of higher-ranking officials in the administration -- including Nixon himself -- were willing, if not anxious, to go along. But Liddy did more than that; he was both the planner and the commander of the scene. He was a possessed, daffy and very dangerous man.

Will, which someone (probably Liddy himself) insisted on calling an autobiography, is far superior to the man. As history and as a study in psychopathology the book is very good. It is the self-portrait of a zealot.

Liddy's account of Watergate is not only believable, but some of what he reveals is front-page news. He suggests, for instance, that Richard Helms, John Mitchell and Richard Kleindienst knew more about his covert operations than previously had been known. There is almost an embarrassment of riches in the book that grows out of his blustery conceit and his freedom from any kind of guilt about what he did. So when he gets down to the accounts of crucial meetings, planning sessions and the actual illegal operations themselves -- the Watergate break-in of June 17, 1972, or the "entry" at the office of the psychiatrist of Pentagon Papers defendant Daniel Ellsberg, or the planned assassination of columnist Jack Anderson -- Liddy is meticulous. His story rings true, and balanced against the other evidence and testimony of the many Watergate investigations, it is credible. A hundred little facts and inferences convince me that he has been as honest as he could be. And he is no longer subject to prosecution for anything in the book that incriminates him, because the statute of limitations has run out.

Among the important new information in this book:

Liddy offers his explanation of why the Nixon White House wanted to break into the Democratic National Headquarters in the first place. The June 17, 1972, Watergate break-in, for which the five burglars were arrested, was "to find out what [Democratic National Chairman Lawrence] O'Brien had of a derogatory nature about us, not for us to get something on him or the Democrats." Liddy offers a detailed account of how and why deputy Nixon campaign director Jeb Stuart Magruder ordered the illegal entry.

The CIA made the expensive charts used to brief Attorney General John Mitchell in early 1972 on the planned illegal GEMSTONE break-in and bugging operations. For me, this suggests more than anything available to date that top CIA officials must have known in advance about Liddy's illegal operations.In my opinion, CIA Director Richard Helms must have been given some inkling from the men over in the CIA graphics department, but Helms has denied it.

Mitchell was willing as attorney general to pay Nixon campaign funds to members of organized crime for their services in a scheme -- never carried out -- to kidnap, drug and ship to Mexico radical demonstration leaders. Liddy quotes Mitchell as saying in response to the proposal, "Let's not contribute any more than we have to to the coffers of organized crime."

Liddy was absolutely serious in his plan to assassinate columnist Jack Anderson and considered four methods, including what Liddy calls "Aspirin Roulette," the placing of a poisoned headache tablet in Anderson's medicine cabinet. The plan was rejected, Liddy says, because "it would gratuitously endanger innocent members of his family and might take months before it worked."

The much-discussed piece of tape holding open a stairwell door in the Watergate office building was put there intentionally so a guard could see it. That way, Liddy reasoned, the guard would assume it had been left innocently by a janitor, whereas a clandestine and inconspicuous method of holding the lock open would arouse more suspicion. (Liddy was at least half-right, because the guard tore off the tape the first time he discovered it, apparently not assuming that anything was amiss. Police were only called when the guard found the door taped a second time.)

Liddy says he delivered logs of wiretapped conversations to Mitchell two days before the Watergate arrests and told him of the planned break-in by announcing that, "The problem [with one of the microphones] will be corrected this weekend, sir." Mitchell has repeatedly denied that he knew of the June 17 break-in in advance; Liddy offers convincing evidence to the contrary.

Richard Kleindienst, who was attorney general on the day of the break-in (Mitchell had by then become chairman of the reelection committee), was given a full account directly by Liddy the day the burglars were arrested. Liddy writes, "I spelled it out for Kleindienst. I told him that the break-in was an operation of the intelligence arm of the Committee to Re-elect the President; that I was running it for the committee and the men arrested were our people working under my direction when they were caught. . . ."

Kleindienst responded, "Jesus Christ," but as the chief law enforcement officer of the nation he apparently failed to tell the federal investigators -- his own people -- what he knew.

Liddy says he does not believe the speculations that James McCord, one of the burglars, was a double agent who knowingly sabotaged the illegal entry.

The autobiographical aspect of the book is equally disturbing. He writes a lot about his father, pain, J. Edgar Hoover, and -- in a generally adolescent way -- about matters sexual. This is all stuff for anyone interested in the psycho-drama. Liddy puts himself forward and on the analyst's couch with embarrassing candor.

For instance, he writes that, as a child, "the most frightening menace of all" was God. Liddy was consumed by shame, dread, fear and self-loathing. The first relief from his bleak childhood was the music he heard on a shortwave radio from Nazi Germany in the 1930s:

"The music . . . was martial and stirring. I lost myself in its strains; it made me feel a strength inside I had never known before . . . Der Fuehrer, Adolf Hitler . . . sean an electric current through my body."

Later, while in prison for his Watergate crimes, he got an associate warden in serious trouble -- a victory hailed by a group of blacks who greeted Liddy one afternoon with raised, approving fists.

Liddy writes, "A feeling of immense power came over me. The martial music and roaring crowds that thundered through the shortwave 40 years before rang through my mind again with undiminished strength as I answered the blacks' salute with the one I'd learned before . . . my right arm shout out, palm down, and was answered by a roar of approval.In that moment I felt like a god."

There is also lots of tough-guy talk and macho stories -- all much less believable than what he writes about Watergate. Liddy is obsessed with guns; some of the book reads like a Smith & Wesson catalouge. For example, one trusted weapon "had a quick-draw ramp front sight, a wide-spur target hammer, and rear sights click-adjustable for windage and elevation." This is the man who says that when he first came to Washington he was "traveling light" and brought only three guns -- "my .357 magnum Smith & Wesson; a snubnosed Colt .38 Special and a big Colt 1911 model .45 caliber semiautomatic pistol."

As part of a program he followed to develop his willpower -- to make himself into a kind of machine, free of emotion and fear -- Liddy literally tested himself by fire. He learned to hold his hand over a candle flame and watch without flinching as his flesh burned. "Suffering. That was the key," to achieving his goals, he writes.

He is clearly able to write without sentimentality about his wife, whom he selected because he thought that she had good genes. "Although one of the reasons I had chosen Frances to be the mother of my children was her size and strength, which should have enabled her to bear half a dozen high-performance children, I certainly had not intended to risk damage by pushing her to design limit," so he does not insist she have the six children he wanted in six years. As an FBI agent he ran a name check on her through the files before marrying her. He also says he checked his neighbors names in the FBI files.

Liddy did not meet Nixon unil the late 1960s. He writes that he was impressed with "his personal warmth" -- a trait not attributed to Nixon by even his most loyal intimates. But who was more loyal to Nixon? He says, to this day, that his refusal to talk during the many Watergate investigations was a great service to the country and to Nixon. "I had, at least, the knowledge that my silence had helped bring him more than two additional years as president."

Liddy will probably be remembered more for his silence, his refusal to break the code, the omerta, than he will be remembered for his book. Yet is another era, say the 1930s, in another country, say Germany, Gordon Liddy might have had a genuinely tragic place in history. There, his schemes might have succeeded and his twisted personality might have flourished.