FORGET ALL THE NEWS stories you've read about Andrew Boyle's first-rate new study of the Philby-Burgess-Macleann spy ring. In England the book was called The Climate of Treason, but here it has been retitled The Fourth Man, presumably to take advantage of the sensation caused when the British government revealed that another spy in the ring -- Sir (and now plain Mister) Anthony Blunt, a distinguished art historian and former curator of the queen's personal collection of paintings -- had confessed his role in 1964. The identification of Blunt, reffered to only as "Maurice" in the text because of Britain's ferocious libel laws, was a major triumph on Boyle's part; but Blunt has only a walk-on role in Boyle's book. Calling him the "fourth man" is arbitrary and misleading. As in all previous studies of the case, which still nags at the British conscience nearly 30 years after the spies themselves were put out of business, the central figure of this book is Harold Adrian Russell Philby, known to friends and colleagues, and to the melancholy history of espionage, as Kim.

The outline of the case ought to be well-known by now. A wave of leftism swept through British universities in the 1930's, a result of the Great Depression, the rise of fascism and the Spanish Civil War. Russian intelligence officers took advantage of this friendly climate to recruit agents among Britain's privileged classes, and then encouraged them to pursue careers in the sensitive professions of diplomacy and intelligence. The most notorious of these agents -- there were a good many others, in addition to Blunt -- were Guy Burgess, Donald Maclean and Kim Philby, three men very different in character and demeanor, but alike in being of a background which inspired automatic, even blind, trust in the British establishment.

It is this dramatically misplaced trust which makes the case so painful for the English. The damage done by the spies is long past, but the betrayal still hurts, not just the spy's betrayal of his country, but an Englishman's betrayal of his honor, and a man's betrayal of his friends. Graham Greene has attempted to exonerate Philby on the ground he was loyal to a cause higher than mere country. It's hard to see what this cause might have been -- international proletarian solidarity? Support for the Hilter-Stalin pact? As excuses go it's pretty thin, and Philby himself has been decently laconic where his "ideals" are concerned, but Greene's very attempt to issue a pardon suggests the depth of the British agony in trying to explain how they could do it.

It such a betrayal had not been unthinkable, the English never could have ignored, overlooked or simply misread the abundant evidence that these three men were just as untrustworthy as they seemed. Burgess, for example, was not only an alcoholic homosexual, but he actually told one friend, Goronwy Rees, that he was a Russian spy and on another occasion casually dropped off a secret communication to his Russian handlers while his puzzled friends watched him do it. Maclean's private life was every bit as chaotic as Burgess', filled with drunken scenes, hysterical rudeness and compulsive homosexual cruising.

Boyle has chronicled their lives in appalling detail. It is hard to imagine how they could have surrendered more convincing evidence of severe internal stress, but their professional colleagues excused them, forgave them, protected them and promoted them from one responsible job to another. Philby kept himself on a tighter rein, but the British Secret Intelligence Service which employed him. and at one time actually put him in charge of counterintelligence against Russia, simply ignored certain suspicious blind spots in Philby's vigilance, as well as the report of a reliable Russian defector of the late '30s, Walter Krivitsky, that the service had been penetrated by a Russian agent. It was a fairly detailed description, and it fit Philby perfectly, but the climate of trust -- good old Kim? He's one of us -- was invincible.

Boyle ably recounts the British half of their double lives until 1951, when the imminence of arrest forced Maclean and Burgess to flee to the Soviet Union, and focused enough suspicion on Kim Philby to end his career in British intelligence. The Latter lingered on in the West, as a correspondent for The Observer in Beirut, until the investigators began to close in on him too, and he was forced to flee in 1963. Just about everyone who knew or even met the three men during their dozen years of spying seems to have talked to Boyle, and he has woven their accounts into a convincing portrait of the pathology of betrayal. It is small justice that Burgess and Maclean seem to have hated themselves more than England, but Philby, who can all but smirk in print as he coyly suggests the torture and death of a man he betrayed, seems to have gotten nothing for his treachery but a daily hangover and the shallow pleasure of knowing something nobody else knows. It is unlikely anyone will ever describe these men, as men, more fully and vividly than Boyle.

But writing about spies is a thankless, Sisyphean task. The facts date with extraordinary rapidity, and it is bound to be a major irony of Boyle's life that his very success -- coming up with something sensational and new about an old case -- made his book all but obsolete before the ink dried. The truth of the matter is that no one outside the Soviet, American and British intelligence services really knows very much about the careers of Burgess, Maclean and Philby as spies, or about the internal investigations which finally cracked the ring of which they were only a part. If Boyle is to be faulted, it is here -- for failing to tell us what he doesn't know along with what he does. He depends heavily on Philby's own memoirs because intelligence officials declined to elaborate on the daily round of Philby's professional life, or the operations he compromised.

Boyle's main contributions to this side of the story -- beyond a small but fascinating handful of details -- are the (correct) identification of Blunt as one of the ring, and the (highly problematic) claim that James Angleton of the CIA turned up a "fifth man" with the aid of two Jewish operatives. Angleton, according to Boyle, was first to learn that Maclean was a Russian spy, began to suspect Philby shortly after he arrived in Washington as British liaison with American intelligence, used the "fifth man" to uncover Burgess, and failed to pass on any of this information to the British. In short, Angleton cracked the biggest Russian spy ring of the postwar world, and then kept it to himself. Boyle does not tell us where he learned these remarkable things, which is fair enough. Textual evidence supports his claim it came from American intelligence sources, and the dramatic confirmation of Blunt's role more than justifies Boyle's confidence in his informants. But at the same time it has to be said that Boyle's account is murky in many respects, overlooks the fact that Angleton did not take over counterintelligence for the CIA unitl 1954, and provides only the lamest of explanations for Angleton's failure to tell the British what he knew, whatever that was. Boyle suggests Angleton was playing a waiting game, fishing for the proof that would convict philby. That just won't wash. Something else happened, I don't know what it was, and Boyle doesn't either.

It is the chronic fragmentariness which makes the subject of spies such treacherous ground for writers. The publication of Boyle's book in England has elicited a number of new names, along with some partial denials, which have the effect of completely reopening the story. Blunt, for example, denies Boyle's claim that he triggered the flight of Burgess and Maclean by telling them British investigators were about to pounce. The "fifth man," identified in the press as a British-born physicist now living in Washington, Dr. Wilfredd Basil Mann, has denied that he played anything like the role assigned to "Basil" in Boyle's book, but he has left open the possibility he was involved in some sort of counterintelligence operation known both to British and CIA officials in Washington in the late '40s and early '50s. Russian penetration of British intelligence was apparently more extensive than ever suggested previously. In Addition to Philby and Blunt, who served in M15 during the war, there was the art dealer Tommy Harris (whose death in 1964 prompted Blunt's confession) and perhaps even another high m15 official involved in counterintelligence, Guy Liddell. Clement Attlee's press Secretary at the time, Philip Jordan, died of a heart attack the night of Burgess' and Maclean's escape, and there is evidence he was a Soviet spy too. A British foreign service officer in the late '30s, John Cairncross, has confessed that he also provided secret information to Burgess before the war. Boyle's book, so brilliantly effective where the lives and characters of Burgess, Maclean and philby are concerned, must now be rewritten to follow up all the new leads which Boyle either discovered himself, or smoked out with his book.

A last question remains: does any of it matter? The ring was closed down 30 years ago, in 1961. The West didn't collapse; we're all still here. Is there any point to worrying this old wound? The question might best be answered by the counterintelligence people, who know the details, but of course they will remain silent. All we can say is that Western intelligence services dream wistfully of having such spies in Russia, that Philby's position at the very heart of the British SIS must have compromised the work of an entire generation, and not of the British service alone; and that the consequences might have been catastrophic if Russia and the West had been at war. Which, of course, was precisely what Philby, in particular, had in mind.