 After the war, Toon joined the United States Foreign Service, receiving postings in Poland, Haiti, and Hungary, before being trained in the Russian language at the Embassy of the United States, Moscow in the 1950s.In 1965, Toon had become the U.S. embassy's third-ranking official when the Russians made accusations that was running a spy ring, which were officially denied, and he was not expelled.He then became the head of the State Department's Soviet Affairs office.