Excerpts from Books and Wikipedia
Gaddis also wrote a biography of Kennan. Kennan came up with the “containment” strategy that the US used throughout the Cold War. Kennan was a Russian diplomat who was familiar with Russian literature, including that by Tolstoy, Dostoevsky, and Chekhov. He believed that the Marx-Lenin philosophy was incompatible with Russian culture as depicted by these and other writers. So, that is why he recommended the containment strategy to wait it out. Eventually, a leader like Gorbachev would come along and Communism would be abandoned. [John Lewis Gaddis, YouTube interview] "Kennan’s 'long telegram' became the basis for United States strategy toward the Soviet Union throughout the rest of the Cold War. . . . To expect concessions to be reciprocated was to be naïve: there would be no change in the Soviet Union’s strategy until it encountered a sufficiently long string of failures to convince some future Kremlin leader—Kennan held out little hope that Stalin would ever see this—that his nation’s behavior was not advancing its interests. . . . What would be needed . . . was a 'long-term, patient but firm and vigilant containment of Russian expansive tendencies.'" [Gaddis, The Cold War, Kindle Location 489]