Oleg Penkovsky was a Soviet military intelligence officer who became a key figure during the Cold War. He is best known for his role as a spy for the United States and United Kingdom, providing crucial information about Soviet missile capabilities and military plans. His intelligence contributions were significant during the Cuban Missile Crisis in 1962. Penkovsky was arrested by the KGB in 1962 and later executed in 1963 for treason. His actions are often credited with helping to avert nuclear conflict between the U.S. and Soviet Union. Penkovsky's story highlights the complexities of espionage and the risks taken by individuals in the name of national security.