George Frost Kennan, who died last week in Princeton, N.J., at 101, was an insecure outsider from Milwaukee, Wis., who was embraced, in ways that sometimes made him squirm, by the clubby coterie of wise men who shaped America's bipartisan foreign policy at the outset of the cold war. He was at heart an intellectual and a historian, which made him a little too edgy and anguished to be a natural diplomat. But while stationed in Moscow at the end of World War II, he became the most influential foreign-service officer in American history by authoring a new strategic doctrine--known as containment--that came to define his nation's foreign policy for four decades.
On Washington's birthday in 1946, after brooding alone at the Moscow embassy, Kennan summoned aides and began dictating a 5,540-word cable, divided into five sections like a Puritan sermon, that called the containment of the Soviet Union's expansionist instincts "undoubtedly the greatest task our diplomacy has ever faced." What became known as "the Long Telegram" shook up the foreign policy establishment, as did a subsequent essay he wrote for Foreign Affairs magazine. His doctrine galvanized an array of initiatives to compete with the Soviets, among them the Marshall Plan, NATO, the World Bank and Radio Free Europe. It was an approach that policymakers today would do well to study as they face a similar global challenge.
Kennan retired from the foreign service 50 years ago to perch at Princeton's Institute for Advanced Study as America's most venerated foreign policy intellectual. Although he retained the moral streak of a Presbyterian elder, it was balanced by a Bismarckian realism. With a clarity of mind to the end, he issued warnings about the dangers of the ideological passions and crusading hubris that he saw infecting America's foreign policy today. --By Walter Isaacson