Who was a principal architect of the containment policy during the Cold War?

The principal architect of the containment policy during the Cold War was George F. Kennan. Kennan, a diplomat and expert on Soviet affairs, articulated the strategy of containment in a famous 1946 telegram known as the "Long Telegram." In this document, he argued that the Soviet Union was expansionist by nature and posed a significant threat to U.S. interests. He suggested that the United States should adopt a policy of containing Soviet influence through diplomatic, military, and economic means, rather than trying to roll back communism where it already existed. This idea became the cornerstone of U.S. foreign policy throughout the Cold War, influencing decisions related to conflicts such as the Korean War and U.S. interventions in various countries.

While Truman's administration implemented containment, and subsequent leaders like Kennedy and Eisenhower adapted the policy to fit their contexts, Kennan is credited as the originator of the containment strategy, making his role pivotal in the early stages of the Cold War.