The Battle of Midway proved pivotal in the United States’ advance across the Pacific, dealing a devastating blow to the Imperial Japanese Navy. Less widely known, however, is that the battle also exposed one of the most significant security failures of World War II—an incident that might have had far greater consequences if not for a handful of fortunate mistakes.
Battle of the Coral Sea
The story begins with the Battle of the Coral Sea in May 1942, a month before the Battle of Midway. Australian-American reporter Stanley Johnston, writing for the Chicago Tribune newspaper, was aboard the USS Lexington (CV-2). Having been vetted by the Federal Bureau of Investigation (FBI), he was the only journalist aboard the American aircraft carrier.
During the engagement, Lexington was sunk by the Japanese. While evacuations were underway, Johnston ran below deck to rescue sailors who’d been badly burned and helped transfer them onto the USS Barnett (APA-5). From there, he and the other survivors began their voyage to San Diego, California, via Nouméa.
Stanley Johnston became privy to top-secret information
While aboard the USS Barnett, Stanley Johnston roomed with Cmdr. Morton T. Seligman, executive officer of the sunken USS Lexington. Seligman was privy to US Navy intel and received a top-secret message from Adm. Chester Nimitz, no. 311221.
While it’s unknown whether he told Johnston or if the reporter happened upon the note, its contents were soon published for all of the United States to read.
Johnston published 15 first-hand accounts from the Battle of the Coral Sea in the Chicago Tribune. He also wrote up a story on the American victory at Midway, with the title, “Navy Had Word of [Japanese] Plan to Strike at Sea.” It was a story so big that it was picked up by the San Francisco Chronicle and published on its front page.
Implied, but not explicitly stated
While the story didn’t explicitly state Japanese code had been broken by the US Navy, it did strongly imply that was the case. It explained that officials had advance knowledge about the attack at Midway, along with the size and schedule of the enemy fleet.
The leak caused an uproar within both the Navy and the US government. President Franklin D. Roosevelt was incredibly upset with the journalist, who was aware that such stories required the approval of Washington. While many agreed Naval personnel should have been more discreet with sensitive information, it was policy that reports written from war zones be sent the Naval Censorship Office before publication.
Stanley Johnston was put before a grand jury
Due to the potential security breach such an article posed, the FBI, the US Navy and the Justice Department all petitioned US Attorney General Francis Biddle to charge Stanley Johnston and Chicago Tribune managing editor Patrick Maloney under the Espionage Act of 1917. The move would be the first and only time the act was used against a journalist.
The first four days of the trial saw witness testimony, with the fifth scheduled to feature Navy brass. The aim was to show the jury how Johnston’s story could negatively impact the country’s war efforts. However, Adm. Ernest King, Chief of Naval Operations, denied the opportunity for his officers to testify. This severely hindered Biddle’s case, as the grand jury found it difficult to indict the men on charges they didn’t fully understand.
Johnston and Maloney were ultimately acquitted of all charges, due to a lack of testimony on behalf of the Navy and because the Espionage Act didn’t cover enemy secrets. This wound up being a blessing in disguise for the Navy, as it meant the matter would soon be forgotten by the American public, lessening the chances of the Japanese learning about the breach.
Aftermath of Stanley Johnston’s actions
As the grand jury investigation moved forward, officials weighed additional measures that could be taken against the Chicago Tribune. Proposals included having the U.S. Navy confiscate vessels carrying newsprint across the Great Lakes or cutting off pulp shipments to the paper’s publisher, Robert R. McCormick. In the end, however, neither option was carried out.
Fortunately for the Navy, Japan never discovered that its codes had been broken. Although Japanese forces periodically updated their encryption systems, the revisions failed to make them secure, and the primary code—JN-25—remained vulnerable to Allied cryptanalysis.
Morton T. Seligman paid a heavy price for his involvement in the leak. Ernest King reassigned him to shore duty and blocked his promotion to captain. The damage to his career proved lasting, ultimately leading to his forced retirement from the Navy in 1944.