What if there were an organization more sinister and powerful than the Mafia, the Central Intelligence Agency, the K. G. B. and Coca-Cola rolled into one?

That's the pleasant if slightly shopworn premise of Robert Ludlum's hefty new thriller ["The Matarese Circle"], which pits the joint talents of a C.I.A. operative and a K.G.B. killer against a Corsican terrorist group that may have been behind the murders of such diverse worthies as Archduke Ferdinand and Leon Trotsky. Now they're out to embarrass both the United States and Soviet Governments by killing off each country's V.I.P.'s and making it look as if the other country had done it….

The fans of Robert Ludlum, as numerous as the leaves on the trees, will delight in "The Matarese Circle," which strictly adheres to formula. Others may feel that the novel is longer than its...