For such a prolific writer, Kennan’s legacy is bound up with two short pieces. One is, ironically, known as the “Long Telegram”—at around 5,400 words, it broke traditional limits for State Department communication. In 1946, the Truman administration was trying to work out its policy toward the Soviet Union, which had only recently been an ally in the war against the Axis powers but now appeared hostile and suspicious. Kennan, who had served multiple postings in the U.S. Embassy in Moscow, provided an explanation. He described the USSR as a “force committed fanatically to the belief that with US there can be no permanent modus vivendi, that it is desirable and necessary that the internal harmony of our society be disrupted, our traditional way of life be destroyed, the international authority of our state be broken, if Soviet power is to be secure.” It circulated quickly and widely.
The next year, Kennan made a second legendary contribution via an article published in Foreign Affairs, which initially appeared under the pseudonym “X.” That article, “THE SOURCES OF SOVIET CONDUCT,” similarly warned that the Soviet Union was driven by ideology. Nonetheless, he insisted, it remained far weaker than the Western world, and “may well contain deficiencies which will eventually weaken its own total potential.” Kennan advised a “policy of firm containment, designed to confront the Russians with unalterable counter-force at every point where they show signs of encroaching upon the interests of a peaceful and stable world.” Though his writings were not the only sources for these ideas, they were forceful and powerful justifications for policies on which the United States was embarking.
But the “architect of containment” soon began to be dissatisfied with the way the contractors were erecting the building he had designed. Already by 1948 he was complaining that he had not intended containment to be a militarized program of confrontation. In the more than 50 years that he lived after that, he was a frequent critic of U.S. foreign policy. Considered one of the founders of realism—the doctrine that the United States should pursue its interests, not have a foreign policy driven by moral considerations—he frequently criticized U.S. military interventions abroad, from Vietnam to Iraq. He believed strongly—and said quite clearly in both the Long Telegram and “THE SOURCES OF SOVIET CONDUCT”—that the United States had to do work at home in order to “measure up to its own best traditions and prove itself worthy of preservation as a great nation.”