George Kennan, the famed Cold War diplomat, believed the West would come to regret NATO expansionism: “[It] would be the most fateful error of American policy in the entire post-cold-war era,” he wrote in the late 1990s. “Such a decision may be expected to inflame the nationalistic, anti-Western and militaristic tendencies in Russian opinion; to have an adverse effect on the development of Russian democracy; to restore the atmosphere of the cold war to East-West relations, and to impel Russian foreign policy in directions decidedly not to our liking.”
