JFK: finger of blame points to the KGB
The young American was agitated, increasingly emotional, and had laid a loaded gun on the table. The Soviet Union must grant him a visa as soon as possible, he pleaded.
His life was being made intolerable by FBI surveillance and he, a dedicated communist, wished to return to Russia.
One of the three Soviet diplomats present took the gun and unloaded it before returning it to its owner. There would be no visa in the near future, he explained calmly.
Dejected, the American gathered up his documents and departed the Soviet consulate, bound not for his previous home in New Orleans, but Dallas.
It was Mexico City, Saturday, September 28, 1963, and the man wanting the visa was Lee Harvey Oswald. Fifty-five days later, he would assassinate John Fitzgerald Kennedy.
This is the standard version of events, as related by one of the "diplomats" present that day, Oleg Nechiporenko. The other two were Pavel Yatskov and Valery Kostikov. All were officers in the KGB.
Kostikov was, according to the CIA, specialised in "executive action" -- sabotage and assassination.
Half a century later, two great traumas of the Cold War era stir in the memory -- the Cuban Missile Crisis of October 14-28 1962 and the Kennedy assassination on November 22 the following year.
In 1979, the US House of Representatives Select Committee on Assassinations concluded that the Soviet government had not been involved. Back then, the nuclear stand-off between East and West had a decade to run, and the finding was as necessary then as in 1963, when a declaration of Soviet involvement could have triggered nuclear war.
Robert Holmes agrees that the Russian government was not involved at an official level but believes events on Cuba are intimately related. A former diplomat, who served in the British embassy in Moscow between 1961-2, he has made a fresh study of that fraught era.
Oswald may have acted alone, thinks Holmes, but he was almost certainly under the control of an outside force. In his new book, 'A Spy Like No Other', he suggests that Kennedy was most likely the victim of a rogue element within the KGB, hardline Stalinists who were incapable of taking the humiliation of Cuba lying down.
They conspired behind the back of Nikita Khrushchev, the Soviet premier, to take revenge on Kennedy, whose cool but resolute stance had forced the withdrawal of Russian medium-range nuclear missiles from Fidel Castro's Cuba.
"Cuba was a humiliation of the first order for these men," says Holmes. "Khrushchev and Kennedy didn't become friends in the wake of Cuba but they were able to see eye to eye, to an extent. They were moving forward, calming the world down.
"This group within the KGB didn't want that; they wanted to fight. They thought Khrushchev should actually have fired off atomic weapons."
The spy of the title is Ivan Serov, a man schooled in the purges of the 1930s, when Stalin sent millions to their deaths.
Appointed head of the KGB by Khrushchev in 1954, he played a crucial role in putting down the Hungarian uprising of 1956, supported by his allies Yuri Andropov and Vladimir Kryuchkov.
Andropov would go on to lead the KGB, and then the USSR from 1982 until his death in 1984. Kryuchkov presided over an attempted coup against the government of Mikhail Gorbachev in 1991.
In 1959, Serov was appointed head of the GRU, Soviet military intelligence. His apparent undoing coincided with the Cuban crisis when a GRU officer, Oleg Penkovsky, was unmasked as a British agent and Serov disappeared into the shadows. Holmes believes these three, Serov, Andropov and Kryuchkov, were the architects of a plot to kill Kennedy.
"These were three stalwarts," says Holmes. "Kennedy is the arch enemy. Something has to be done.
"Oswald? Yes, he may have been erratic and was a focus of suspicion because he had emigrated to the Soviet Union before returning to the US. But when you need an expendable assassin, you have to work with what you've got."
Oswald's treatment in Mexico City that weekend in September 1963 was highly unusual. "You would not have had three senior supposed diplomats meeting with a person of no importance on a Saturday morning," he says.
"Yes, he had spent a couple of years in the Soviet Union but he wasn't anybody special. He had applied on the Saturday morning for a visa that was going to take four months to come through.
"Immediately after the meeting with Oswald, they sent a classified telegram to Moscow. You don't do that for someone who walks in for a visa. There was something special going on there."
Holmes felt the pressure exerted by the Soviets while in Moscow. "You lived and worked on the basis that there were microphones in every wall. When you went to a restaurant you felt you had been placed at a specific table with a microphone attached to it. You could never relax."
The Kennedy conspiracy industry is cranking up for the big anniversary. Holmes, however, admits he could be wrong, but thinks a rogue element in the KGB is more plausible than Mafia-CIA-Military-Industrial-Complex hypotheses.
"I would say that it is all circumstantial evidence," he says, "but if there was evidence that would stand up in court, we wouldn't be sitting here talking about it. Other assassination theories require some kind of leap of faith; with mine, it is only a little step."
But Oswald? Surely he would have told all, had Jack Ruby not shot him? "If he hadn't shot Officer J D Tippit after the Kennedy shooting, he may have got away that day, but I'm pretty sure the KGB would have either spirited him back to the Soviet Union or killed him.
"There's no way they could have allowed him to be captured." (© Daily Telegraph, London)