St. John spent the next 15 years based in Switzerland, before returning to the United States, always roaming the world to write and broadcast major events on radio or in magazines and books. His work included research around the globe for the World Book Encyclopedia.
He became regarded as a Middle East specialist after covering the war for Israeli independence. St. John covered the Eichmann trial and five Arab-Israeli wars, including the 1982 Israeli invasion of Lebanon. At that time, he was 80, by far the oldest of the hundreds of reporters on hand, and the only one who had covered all four previous Arab-Israeli conflicts. He wrote a dozen or so books about the Middle East and Judaism, including well-reviewed biographies of David Ben-Gurion and Gamal Abdel Nasser.
An eloquent non-Jewish spokesman for Jewish causes, he maintained close ties with the Jewish state and was honored by Jewish and Israeli institutions. David Ben-Gurion, Israel’s first prime minister, called him “our goyisher Zionist”.
A few of his books were non-documentary. The story of Rudolf Kastner, the Zionist Romanian-Hungarian Jewish leader who was accused of betraying his people to the Nazis, was the base upon which he built his fictional novel The Man who Played God (Doubleday, 1962).
All in all he wrote 23 books, the last of which in the year 2002, when he turned 100 years old, an autobiography. He also wrote many articles, some of which got published as booklets.
St. John was married twice. He married first to Eda Guerrieri (marriage dissolved), and second in 1965, to Ruth Bass. He died in Waldorf, Maryland, on February 6, 2003