BOOKS: Secrets, lies and Russia's atomic spies

Venona: The Greatest Secret of the Cold War by Nigel West HarperCollins pounds 19.99 Venona: Decoding Soviet Espionage in America by John Earl Haynes and Harvey Klehr Yale pounds 19.95 The Official History of the Security Service 1908-1945 by John Curry The Public Record Office pounds 5

W hen the news broke 50 years ago in September that the Russians had exploded their first atomic bomb, the American Intelligence services were not as traumatised as might be expected. They already knew from the most brilliant decoding coup of the Cold War that their country's nuclear secrets had long since been betrayed.

Furthermore they were on the track of the most dangerous atom spy, then known to them only under his cover name of "Charles", but whom within six months they and MI5 would unmask as Klaus Fuchs, a German emigre physicist whose infiltration into the heart of the Manhattan project had given Moscow all it needed to detonate a nuclear device.

What could not be revealed at the trials of either Fuchs or his courier and spy "middlemen", Julius and Ethel Rosenberg, was that they had been trapped by Operation Venona, a painstaking exercise in decryption which, while not laying bare all the secrets of the Soviet codes, did identify more than 300 Americans as actual or potential traitors - and not a few Britons, as Nigel West reveals.

Venona was "live" for only a short period in the war and immediate post- war period but produced results for many years afterwards despite having been betrayed to the Russians by Kim Philby. It was wound up in 1980, by which time the trail had grown too cold, but its secret was zealously guarded - even from President Truman - for more than 40 years until in 1995 the CIA gave the green light for its release. The clinching argument Haynes and Klehr used with the CIA was that they had been given privileged access to top-secret Russian files which proved for the first time the extent to which the Communist Party of the United States had betrayed their country. The 3,000 telegraphic cables through which Soviet spies and fellow-travellers in the United States kept their masters in Moscow informed on the nuclear programme, conventional weapons development and diplomatic traffic completed the circuit in the two historians' researches - now digested into the clearest account we are likely to get of the immediate post-war world as it passed under the shadow of the bomb.

The release of the files at an American seminar, which British Intelligence experts were forbidden to attend, was bound to start a publishing race and Nigel West's book suffers in comparison from an over- stuffing of the minutiae of espionage links - Venona telegrams are often cryptic enough - and a rather stodgy style.

Which is a pity as by naming names in the fellow-travelling British Establishment he will have won himself fresh kudos as a first-rate espionage sleuth. Startlingly, he names the leading Cambridge geneticist, Professor J B S Haldane, and Ivor Montagu, son of Lord Swaythling, as NKVD sources on British weapons development during the war, but claims that even when decoders identified them as "Intelligensia" and "Nobility" in the 1960s, MI5 declined to prefer any charges to preserve the programme's secret.

Montagu, West reveals, headed a spy ring, known to Moscow Control as "X Group". He says, "hitherto completely unsuspected, this spy ring operated in London undetected and it was not until GCHQ (the British Code and Cypher HQ) began reading the GRU (Russian military Intelligence) traffic in the mid-1960s that the breathtaking scale of the organisation, and the social status of its membership, was understood."

The two books complement each other, West often filling out the British side of a transatlantic Intelligence operation. The Russian codes, originally considered "unbreakable", were only cracked, as the preamble to the official release states, "through sweat of the brow analysis" - some of it by the 19-year-old cryptanalyst Cecil Phillips, who first identified many of the telegrams as NKVD and GRU. The size of the task was so enormous - ironically the Russians' code for the atom bomb project was "Enormoz" - that a time-lag of many years before a tantalising clue could be turned into a hard identification led to many spies slipping through the net, most notoriously Kim Philby and Donald Maclean.

The damning cable identifying Maclean through his wife's pregnancy, sent by Moscow on June 28 1944, only fell to British "prolonged cryptographic attack" on March 30 1951. Unfortunately "the smoking gun" missed its target and Philby was able to warn his co-agent. Philby was linked by Venona to the cover name Stanley in 1945 but the relevant codes were not broken until after his flight in January 1963.

A major difference of opinion between the American and British authors centres on the culpability of J Robert Oppenheimer, director of the Manhattan Project and "godfather" of the two atom bombs. Was he a spy? No, say Haynes and Klehr; none of the cables suggests any compromising relationship with Soviet Intelligence, but in his debriefing by the FBI which led eventually to his removal from the leadership of the H-bomb project, this former member of the Communist Party of the United States "may have overlooked the conduct of others whom he had reasonable grounds to question". By which could be meant the spies "Perscus" and "Quantum", known from Venona to have flourished at Los Alamos but who were never identified beyond doubt. Very possibly, says West, who identifies Oppenheimer with the code name "Bill of Exchange" and cites the former NKVD/KGB officer in charge of destabilisation operations against Western targets, Sudoplatov, as saying that Oppenheimer had made available five reports on the workings of the A-bomb and had introduced Fuchs to Los Alamos. The case rests ...

The Security Service Official History, published by the Public Record Office, was an in-house history never intended, like Venona, for public consumption. Bearing in mind he was writing in 1946 John Curry, its MI5 author, makes some tantalising points; a Communist had access to Cabinet papers, reflecting what we now know from Venona was happening in the White House, where Roosevelt's most trusted aide is now revealed to have been a Russian agent; "one Communist each was discovered in the Security Service, SIS and SOE, although there was no reason to think that any of them had been able to give away information of first-class importance" (all were sacked); and "other inquiries had shown there were Communists in institutions engaged in scientific research and industry with access to various secret technical processes."

In their case for opening Venona, Haynes and Klehr said it was "improper and ironic that American scholars could find messages linked to the Moscow end of Soviet cable traffic in an open Russian archive but that the messages themselves were locked up in a closed American archive." As we await the passage through Parliament of the Government's emasculated Freedom of Information Bill, researchers in the British records who are often stymied by the same rules as they apply to Anglo-American secret records can only hope for the precedent to be recognised.