Assassination played a key role in Stalin’s foreign policy. In 1939 Stalin personally ordered the dispatch of a secret task force to murder Leon Trotsky in Mexico, where he had taken refuge. Even at the outbreak of the Second World War, gaining intelligence on Adolf Hitler was a lower priority than liquidating the great heretic. Trotsky’s assassin, Ramón Mercader, who kept the Stalinist faith throughout his twenty years in a Mexican jail, was made a Hero of the Soviet Union on his release. During the early years of the Cold War, Stalin attached almost as much importance to assassinating Marshal Tito, who had succeeded Trotsky as the great heretic of international communism. Tito’s assassin was to be the Soviet illegal (deep-cover agent) Iosif Grigulevich, who had formerly been involved in the plot to kill Trotsky. Remarkably, Grigulevich succeeded in posing as a Costa Rican diplomat under the alias Teodoro Castro. As Costa Rican ambassador in Rome and non-resident envoy to Belgrade, he gained personal access to Tito.

After Stalin’s death, the plot to kill Tito was abandoned and Grigulevich was recalled to Moscow, where, under his real name, he began a successful academic career as an expert on Latin America. Stalin’s successor, Nikita Khrushchev, supported a more limited policy of foreign assassination, particularly directed at