Timothy Wilford

Wilford, Timothy. "Decoding Pearl Harbor: USN Cryptanalysis and the Challenge of JN-25B in 1941." The Northern Mariner 12, no. 1 (Jan. 2002): 17-37.

"[A]n examination of key letters and message-intercepts ... suggests that the USN could partially read Japanese naval traffic on the eve of the Pacific War.... The new evidence lends more support to revisionist interpretations than to traditionalist interpretations.... Future interpretations of USN cryptanalysis must assess how much [emphasis in original] was currently read through JN25B decryption."


Wilford, Timothy. "The Enemy Within and the Pacific Threat: Canadian Security Intelligence in British Columbia, 1942–45." Intelligence and National Security 27, no. 4 (Aug. 2012): 531-558.

From abstract: "Recently declassified intelligence files show that several factors influenced the way in which Canadian authorities viewed 'the enemy within' and 'the Pacific threat'. During the Pacific War, the Canadian conscription policy, public complacency, wartime allegiances and enemy activity along the coast all impacted the way in which security intelligence was collected and interpreted in British Columbia."


Wilford, Timothy. Pearl Harbor Redefined: USN Radio Intelligence in 1941. Lanham, MD: University Press of America, 2001.

For Ford, Journal of Strategic Studies 26.4, "[t]he main strength of Wilford's book lies in its meticulous analysis of the relevant archival sources. The author is careful to avoid arriving at conclusions which cannot be supported by the evidence which he has consulted. Of equal importance, previous hypotheses regarding the intelligence failure at Pearl Harbor are paid due heed, with a careful evaluation of their strengths and weaknesses."

Kruh, Cryptologia 26.2, notes that "[f]rom the outset, Wilford declares his loyalty to the revisionists; his views echo their claims of censorship, missing documents, illogical statements, and overlook or belittle warnings issued between November 24 and 28." Wilford, Cryptologia 27.1/70-71, takes exception to Kruh's dismissal of his work. He states that his central thesis, which he believes is supported by archival and other research, is that "the USN gathered sufficient radio intelligence to predict the likelihood of a Pearl Harbor attack, although the Hawaiian commanders received insufficient forewarning." Kruh, Cryptologia 27.1/71-72, responds to Wilford's letter.

See also, Jacobsen, "Foreknowledge of Pearl Harbor? No!: The Story of the U.S. Navy's Efforts on JN-25B," Cryptologia 27.3 (Jul. 2003): 193-205.


Wilford, Timothy. "Watching the North Pacific: British and Commonwealth Intelligence before Pearl Harbor." Intelligence and National Security 17, no. 4 (Winter 2002): 131-164.

"Throughout 1941, British Intelligence pointed to a war with Japan in South-East Asia.... British Intelligence, according to some sources, also suspected that a Japanese attack on Pearl Harbor was imminent, an assessment shared with the United States."

Bath, NIPQ 19.3, notes Wilford's thesis that the Japanese fleet may have used low power, low-frequency ship-to-ship communications that allowed British DF stations to locate the ships advancing on Pearl Harbor. That information may have been passed to the U.S. authorities. The reviewer comments: "Much conjecture, little new, hard evidence."

[UK/WWII/FEPac & Services/Navy; WWII/PearlHarbor]

Return to Wil-Wilf