If you've ever wondered whether Israel really has an atomic bomb, or why Sadat really went to Jerusalem, or even why the 1973 Yom Kippur war came to such an implausible end, there are some highly imaginative answers to be found in this new novel by the author of "Eye of the Needle."

Ken Follett's "Tripple" is the breathless account of how a 43-year-old Cockney Jew, turned Israeli secret agent, almost single-handedly saved the Middle East from Armageddon or worse back in 1968.

Unfortunately, Follet's style is almost as breathless as his plot, which serves up a score or more bodies, both dead and damaged, many of them the victims of Nat Dickstein, the dread Mossad agent, whom Follett describes as being short, slight and all bones. In fact, the more Follett describes him, the more Woody Allen comes to mind.

What Follet has done is to take the outline of the Plumbat Affair and embellish it with plot and counterplot involving KGB agents, a Mafia satrap, a beautiful airline hostess, an Oxford don, and a gaggle of Moslem spies of various hues and persuasions.

The plumbath Affair, recorded in fascinating detail a few years back by a team of British journalists, involved the disappearance somewhere in the Mediterranean of 200 tons of uranium ore, enough to build about 30 atomic bombs. Nearly everyone suspected the Israelis of having either hijacked or pirated the ore, but nothing was ever proved. Follet's novel provides a rather bizarre account of how it all might have happened. The gullible may well be convinced.

The tale begins back in 1947 at a sherry party in the home of an Oxford Arabist, which is attended by Nat Dickstein, the Cockney Jew, two foreign students, one from the Soviet Union, the other from Palestine, and an Italian-American who is a Worlk War ii buddy of Dickstein's.

Twenty-one years later the Russian Student is a high-ranking KGB officer; the Palestinian, now homeless, works for Egyptian intelligence in Europe, and the Italian-American has acquired the Mafia franchise in the northeastern United States. The Oxford Arabist is still at Oxford, but his daughter has grown up into a gorgeous airline stewardess who flits about the world.

And Dickstein, of the course, has become the Israeli agent who is handed the assignment of somehow procuring 200 tons of yellowcake, or uranium ore, so that Israel can build some atomic bombs to match the ones the Egyptians are supposed to be building out there in the desert. Dickstein flies to Luxembourg where Euratom headquarters is located and beats hell out of a Euratom employe's homosexual lover and then blackmails the employe into revealing information about European uranium shipments.

Alas, just as he is leaving Luxemborg. Dickstein bumps into his old classmante, the Palestinian, now moonligthing as a small-time Egyptian agent. Supicious, the Palestinian alerts Cairo and Cairo alerts Moscow.

Dickstein races aroung Europe and the United States, locating uranium ore shipments, setting up a dummy Liberian shipping company, buying freighters, and fighting with his crusty superior back in Tel Aviv. in the midst of all this he falls in love and hops into bed with the airline stewardess daughter of the Oxford Arabist. It's Dickstein's first sexual experience in 24 years and if you can believe that, you will have no trouble at all with the rest of the book.

The novel's climax is finally reached in a piratical shoot-out somewhere in the Mediterranean. The full flavor of this episode can be gained from just one line: "i've heard of being armed to the teeth, but this is ridiculour,' said Nat Dickstein, and they all laughed."

In an apparent attempt to avoid stereotype by making his hereo short, skinny, bespectacled and middle-aged -- but still capable of incredible physical feats -- Follet has wound up with an unfortunate caricature. There are enough stereotypes in the book already -- the Russian, the Palestinian, the Mafia cheiftain. But all seem for more real than does Nat Dickstein, secret agent.