A scene from the 2019 movie Midway depicting part of the US Pacific Fleet in World War 2 just before the Battle of Midway.
GENERALLY, it goes without saying that a nation must balance press freedom with a need to keep vital information secret – especially when a war is raging. On one hand, a lack of information could spur panic should unfounded rumours be taken as true, but on the other any information that gets across to the enemy could give them a significant advantage. It has been said in newspaper articles, in books and online that the Chicago Sunday Tribune had inadvertently leaked that the United States had broken Japanese naval codes in the lead-up to the Battle of Midway.
Is this true?
Verdict:
2050655
TRUE
This is in fact true, and while the front-page article in question – one headlined "Navy Had Word of Jap Plan to Strike at Sea" - did not say it explicitly, a reading of the text of the story clearly stated that the US Navy knew the Japanese plans in advance and was therefore able to ambush them.
As written in a 2017 Washington Post article in the run-up to the 75th anniversary of the Battle of Midway, the article published by the Chicago Sunday Tribune contained key specifics; the three parts of the planned Japanese attack and also gave details of the ships involved down to their names and types.
As historian Elliot Carlson said when quoted by the Washington Post, "any knowledgeable reader of that story would have known that [it] had to come from American cryptanalysis of the Japanese naval code."
Indeed, as the late historian John Prados wrote in 2017, both the Navy and the then-administration of President Franklin D. Roosevelt knew that the details in the article matched a May 31, 1942 top secret dispatch sent by US Pacific Fleet commander Admiral Chester W. Nimitz.
"There were other equally disturbing elements in the news story; it attributed the knowledge to 'naval intelligence' and sourced it to Washington, almost directly implicating the Navy’s codebreaking operation," said Prados.
He added in his article for George Washington University's National Security Archive that the Navy were able to trace the leak to Chicago Tribune war correspondent Stanley Johnston.
Prados wrote that Johnston, who survived the sinking of the aircraft carrier Lexington during the May 1942 Battle of the Coral Sea had access to naval communications while being ferried back to the US on the transport ship Barnett – and this was also mentioned by Carlson in his article.
"That particular dispatch showed up on the Barnett. It was not intended to go there, but it turned out the transport ship had the equipment to decode whatever it wanted to," said Carlson.
He added that Johnston had shared a room with a senior officer of the Lexington, who would have had access to the message in question.
"So you put him in the same room with the dispatch, and the Navy and everybody else put two and two together. Much of the content of Nimitz’s dispatch appeared in Johnston’s story."
This ultimately led to a move to legal action, and a grand jury was set up in Chicago in August 1942. However, no one was charged with the leak and the testimony heard by the grand jury was sealed until December 2016.
With all this said, the million-dollar question; did the leak cause any damage? The answer is no. The Japanese changed their codes anyways, but that was because they were due to be changed.
As Carlson said, "they never heard of the article."
References:
1. https://www.washingtonpost.com/news/retropolis/wp/2017/06/05/unsealed-75-years-after-the-battle-of-midway-new-details-of-a-critical-wwii-press-leak
2. https://nsarchive.gwu.edu/briefing-book/intelligence/2017-10-25/secrecy-leaks-when-us-government-prosecuted-chicago-tribune
