One of the recurring themes in the histories of men and nations is the idea that we can do what no one else has done because of our better [morals, understanding of history, philosophy, intelligence etc.:] (chose one). It's an almost mathematically precise pattern that we seem doomed to repeat. The verbal approximation it is: idealism leads to hubris leads to vice leads to downfall. Rinse an repeat. Niebuhr incisively confronts this historical pattern as it existed in America and the world in the 1950's, and, since it's a pattern, his analysis remains just as relevant today as it was then.