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. Walter Lippmann; drawing by David Levine 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?…