Nineteen years after the Cuban missile crisis nearly sparked a nuclear war, Fidel Castro asked the Soviet Union to redeploy atomic weapons to his island, says a new book based on reports by Moscow's KGB intelligence agency.

The book, based on documents revealed by KGB archivist Vasili Mitrokhin when he defected in 1992, makes other bombshell allegations as it tracks KGB operations around the Third World in the 1960s and '70s:

- The KGB documents record actual and proposed payments to Chile's Salvador Allende totaling $420,000 both before and after his election as president in 1970.

- Costa Rica's Jose ''Pepe'' Figueres received $300,000 from the KGB for his 1970 presidential campaign and $10,000 afterward.

- Carlos Fonseca, founder of Nicaragua's Sandinista National Liberation Front, was ''a trusted KGB agent'' code-named GIDROLOG.

- Nicaraguan Manuel Andara y Ubeda was a KGB agent who led a group of Sandinistas tasked by Moscow in the late 1960s to scope out the U.S. border with Mexico for possible targets for KGB sabotage teams.

- The KGB ''trained and financed'' the Sandinistas who seized the National Palace in Managua and dozens of hostages in 1978. A senior KGB official was briefed on the plan on the eve of the raid, led by Eden Pastora, aka Comandante Zero.

Pastora could not be reached for comment, though the book does not refer to him as a KGB agent. All the agents identified by name in the book are now dead.