Before writing this book, Weinstein made his mark by demonstrating -- to his own initial surprise, but with overwhelming evidence -- that Alger Hiss really was a Soviet spy. Weinstein's Russian colleague, Vassiliev, had a brief inglorious stint in the KGB before leaving his homeland for a journalism career in the West. Together, they have now produced a remarkable account of "the golden years" of Soviet espionage in the United States, from the early 1930s to the beginning of the Cold War. Many of their stories are well known, but they also include new and interesting material from both American and KGB archives. This was the age when ideology, not mere greed or spite, fertilized the ground for espionage, and it yielded an appallingly rich harvest: treason by senior U.S. government officials and Soviet access to the secrets of the West's most potent weapons. Fortunately, a Soviet-American war never broke out, so the full effects of the Soviet espionage successes were never felt. Undoubtedly there is still much to uncover about this period, but this engaging book will hold the ground for some time to come.