After retiring from government service near the end of President Jimmy Carter’s term, Mr. Henze became a consultant for the Rand Corp., a think tank. He wrote widely about the history and politics of Ethiopia and Central Asia in mainstream publications and several books.
Perhaps his best-known book was his first, “The Plot to Kill the Pope’’ (1983), an investigation into the 1981 attempted assassination of Pope John Paul II, who was shot four times while addressing a crowd at St. Peter’s Square in Vatican City.
A Turk, Mehmet Ali Agca, was convicted of the shooting and spent 19 years in an Italian prison.
Mr. Henze argued that Agca, who offered several contradicting explanations for his actions, had been part of a conspiracy involving the Bulgarian and Soviet secret police.
His conclusion was the result of an exhaustive examination into Agca’s connections with suspected terrorist organizations. Using a wide range of sources across Europe, Mr. Henze, who spoke fluent Turkish, reconstructed the would-be assassin’s journey to St. Peter’s via Iran, Bulgaria, and Germany.
According to Mr. Henze’s book, Soviet officials saw the Polish-born pope — and his support for Poland’s Solidarity movement and human rights in general — as a threat to the communist empire’s stability.
Another book published soon after Mr. Henze’s — “The Time of the Assassins’’ by American journalist Claire Sterling — made the same argument, though Mr. Henze’s probed deeper into geopolitical analysis. The two volumes played a key role in opening debate about the attempted slaying.
Writing in The New York Times in 1984, author Edward Jay Epstein declared that Mr. Henze’s volume “provides a brilliant and completely original analysis of sponsored terrorism in Turkey — a subject that, unless new evidence comes to light about the shooting of Pope John Paul, will probably prove to be of more enduring interest than the papal assassination plot.’’
The plot has remained a subject of debate for decades and inspired several books, including the Tom Clancy novel “Red Rabbit’’ (2002).
The so-called “Bulgarian connection’’ was endorsed by the CIA. But in 1991, former agency analyst Melvin A. Goodman told the Senate Intelligence Committee that high-ranking CIA officials had pressured staff to conclude that the Soviet KGB had ordered the pope’s assassination.
“The CIA had no evidence linking the KGB to the plot,’’ Goodman said.
