The Long Telegram was a pivotal communication penned by American diplomat George F. Kennan from Moscow in February 1946. Kennan served as the chargé d'affaires at the U.S. embassy and was tasked with analyzing Soviet intentions and strategies. In his 8,000-word telegram, he presented a detailed account of Soviet behavior, expressing that the Soviet Union was inherently expansionist, motivated by a mixture of ideological fervor and a desire for security. Kennan urged the U.S. to adopt a policy of containment to strategically counter Soviet ambitions. He argued that this would require a combination of diplomatic, economic, and military measures to thwart Soviet expansion without provoking a direct confrontation that could lead to a nuclear conflict. The sending of the Long Telegram occurred against the backdrop of rising tensions between the United States and the Soviet Union, marking the early stages of the Cold War, and it reflected the anxieties that many American officials felt about the future of international relations in a post-World War II context.

Kennan's analysis emphasized that the Soviet regime was reactive rather than proactive and held a perception of insecurity shaped by its historical experiences. He believed that the Kremlin would be willing to negotiate but would also seize every opportunity to expand its influence. His assessment encouraged American policymakers to devise careful strategies to contain Soviet influence globally. The insights provided in the Long Telegram heavily influenced U.S. foreign policy and laid the groundwork for the Truman Doctrine and the Marshall Plan. Kennan’s recommendations would become a shared framework for numerous policies aimed at containing communism throughout the Cold War.