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Fascinating and Lesser Known People Who Changed American History

Khalid Elhassan May 5, 2020 33 min

Normandy landings - Operation Overlord — Men of the 320th in Normandy. YouTube

31. What Is “AF”?

American cryptanalysts had cracked Japanese ciphers, and knew that they planned to attack a target codenamed “AF”. However, nobody was sure just what AF was. So Navy cryptanalyst Joseph Rochefort devised a ruse to trick the Japanese into showing their hand.

Suspecting that AF was Midway Island, Rochefort directed Midway’s radio station to send an uncoded message, stating that its water purification system had broken down, and that the island was running out of drinking water. 24 hours later, American codebreakers intercepted a Japanese message to the effect that “AF” was running out of water. With the identity of AF thus confirmed, Chester Nimitz, commander of the Pacific Theater, sent his carriers to the vicinity of Midway, to wait in ambush for the Japanese.

Written by

Khalid Elhassan

A lifelong history buff, I developed a particular passion for WW2 history as a child, when I spent hours listening to my grandfather, enraptured, as he recounted his wartime experiences in the British East African Campaign and with the British 8th Army in North Africa.

I graduated with a history BA from George Mason University, then went on to get a JD from the University of Virginia School of Law. After lawyering for a decade, I moved to sunny Rio de Janeiro and a less demanding career, opening a tourism agency in Copacabana.

A big chunk of my free time is spent blogging (you can follow me on Quora https://www.quora.com/profile/Khalid-Elhassan ) or freelance writing, mostly about my favorite subject, history.