American diplomat George F. Kennan’s containment doctrine, which provided the strategic foundation for the West’s victory over Soviet Communism in the Cold War, turns 70 this year. That, I suppose, is reason enough to take a look back at what surely must be counted among the most successful geopolitical concepts in modern history.

But there are at least two other good reasons for revisiting the remarkable cluster of ideas that made their first public appearance in the journal Foreign Affairs in July 1947, triggering a spirited public debate over U.S. relations with our wartime ally, the Soviet Union, and the shape of the postwar international order, that was to last for many months.

The first is that the Cold War is a completely foreign country to most Americans, especially those younger than 40. Even those of us considerably older than 40, who lived through a significant portion of that mammoth, all-consuming conflict, seem to have consigned the struggle to the deep backwaters of memory.