In July 1914 the twenty-four-year-old Walter Lippmann was traveling in Europe to celebrate the completion of his second book, Drift and Mastery, to recruit British writers for the magazine he was cofounding, The New Republic, and to spend two weeks walking through the Swiss Alps. But when Austria declared war on Serbia, his hopes for a hike, at least, were curtailed. He returned to London as the continent descended into conflict. The sudden force of events and his powerlessness in the face of them made a deep impression on the young man. “Nothing can stop the awful disintegration now,” he wrote on August 2 to his friend Felix Frankfurter, the future Supreme Court justice, back in New York. “Nor is there any way of looking beyond it; ideas, books, seem too utterly trivial, and all the public opinion, democratic hope and what not, where is it today? Like a flower in the path of a plough.” The war was all-encompassing and yet impossible to experience except vicariously, through newspapers: “There is the worst event in …