SECRET MESSAGES: Codebreaking and American Diplomacy, 1930–1945.

By David Alvarez. University Press of Kansas. 292 pp. $35

Even more than the Central Intelligence Agency, the National Security Agency (NSA) suffers from a schizophrenic attitude toward disclosure. On the one hand, even a public hint of its supersecret work intercepting and decrypting signals has always been anathema. On the other hand, success stories are vital PR for any bureaucracy dependent on congressional funding. In 1996 the proponents of disclosure briefly gained the upper hand, and NSA declassified some 5,000 files on America’s code-breaking activities during World War II. (If you’ve got to have a success story, it’s hard to beat World War II.) Pieces of the story had come out earlier, but many gaps remained.

In this lucid, comprehensive, and frequently entertaining account, Alvarez, a professor of politics at St. Mary’s College in California, helps fill two of the largest gaps. One is the human story of decoding hundreds of thousands of messages a month sent by enemies, neutrals, and allies alike. The new archival records and other sources (including declassified NSA oral histories and the author’s own interviews with veterans) permit the first reconstruction of day-to-day life at Arlington Hall, the U.S. Army’s wartime code-breaking headquarters in Arlington, Virginia—the mind-boggling work, the frustrations, the strokes of incredible luck, and the cast of extraordinary characters, including the cryptanalyst who sat with his feet in a wastebasket to protect himself from the imagined ill effects of drafty offices.

The other gap Alvarez fills is the effect of this intelligence on American foreign policy and diplomacy. Code-breaking had an undeniable impact on military operations, but, before the 1996 releases, relatively little was known about Arlington Hall’s work on foreign diplomatic traffic. Alvarez’s surprising yet convincing conclusion is that the effect of this work was slight: The Allies’ policy of unconditional surrender, combined with Franklin Delano Roosevelt’s expectation that he could carry foreign leaders with him "through the exercise of will and persuasive charm," undercut the influence of signals intelligence in top policy circles.

Despite this admittedly disappointing conclusion, Alvarez tells a classic tale of secret agencies and intrigue. The army, bringing in some very unmilitary people to get the job done, emerges as a bureaucratic hero. Immediately after Pearl Harbor, it commissioned Alfred McCormack, a prominent New York lawyer with a tough legal mind, to shake up its intelligence system. McCormack created a new Special Branch within Arlington Hall to sift and analyze the code breakers’ output and ensure that it at least reached top officials throughout the government. He filled the Special Branch with so many high-powered lawyers that people in the War Department began calling it the best law office in Washington.

In one of the book’s most telling anecdotes, code breaker William Lutwiniak finds himself facing the prospect of being drafted after Pearl Harbor. His boss, Captain Harold Hayes, tells him to go to the army recruiting station and enlist. There, Lutwiniak is sworn in as a private and handed his orders: Report to Captain Harold Hayes for active duty. Back at Arlington Hall, Lutwiniak goes to see the captain, who promotes him on the spot to sergeant and tells him to get back to work and not to worry about basic training. There are lessons here for today’s very bureaucratic intelligence bureaucracy.

—Stephen Budiansky