2. Joseph Stalin of the Soviet Union
Joseph Stalin’s NKVD (People’s Commissariat for Internal Affairs) was instrumental in enforcing his regime and conducting extensive foreign espionage operations. These efforts included infiltrating Western governments and the Manhattan Project, the U.S. initiative to develop the atomic bomb. The NKVD’s clandestine activities were pervasive, creating an atmosphere of fear both domestically and internationally. For more details on Stalin’s espionage activities, you can refer to this article (en.wikipedia.org).