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The Pearl Harbor ‘Winds Message’ Controversy: A New Critical Evaluation


Kendrick Frazier

Skeptical Inquirer Volume 33.2, March / April 2009

A new critical investigation by the National Security Agency confirms that a Japanese so-called ‘Winds execute’ message was not heard until hours after the attack on Pearl Harbor began on December 7, 1941, and, in any event, contained no actionable intelligence.

It is not every day that one receives a report in the mail from the supersecret National Security Agency. NSA is the U.S. intelligence agency responsible for the collection and analysis of foreign communications and foreign signals intelligence. And when the report investigates the history of one of the long-disputed contentions about the worst war of the twentieth century, it deserves special attention.

The Japanese attack on Pearl Harbor on December 7, 1941, continues to inspire suspicion in some quarters that the U.S. knew it was coming. Some revisionist and conspiracy writers, historians, and critics of the Roosevelt administration contend that the U.S. intercepted a Japanese message that was a clear warning of the impending attack on the U.S. fleet at Pearl Harbor. Some further contend that this so-called “Winds Message” had been revealed to senior American military and civilian leaders. The implication is that the attack might therefore have been prevented.

The story long ago acquired near-mythic status in some circles and has never quite gone away. This group of believers may even have grown in recent years due to the proliferation of Web sites on the Internet with entries about the Winds message.

Historians Robert J. Hanyok and the late David P. Mowry of NSA’s Center for Cryptologic History have now published a new, detailed documentary history of the Winds message controversy in an attempt to clear up the issue and provide source documents for historical scholars and researchers. NSA recently issued the 327–page report (“West Wind Clear: Cryptology and the Winds Message Controversy”), which includes images of all the standard critical documents—as well as many never before seen. The authors debunk the view that a clear warning message was monitored before the attacks.

Hanyok told the Skeptical Inquirer that he believes his report “will dispel any further reference to a ‘Winds execute’ message being heard before the attack,” at least in conventional and academic circles. He says he holds few such hopes regarding most conspiracy-theory bloggers, unless they actually read the report. “Some conspiracy buffs might change their minds if they read my book.”

In a foreword, NSA historian David A. Hatch says Hanyok and Mowry “have made a significant contribution to our knowledge and understanding of two of the event’s controversies, the Winds Message and the state of U.S. communications intelligence prior to the Hawaiian attack.”

Japan’s coded Winds message was intended by the Japanese foreign ministry as an emergency method to alert Japanese diplomats abroad that relations between Japan and the U.S., Great Britain, or the Soviet Union were about to take a downturn. They could then destroy cryptographic materials or sensitive messages.

One method involved placing innocuous-sounding phrases about the winds in weather forecasts transmitted by short-wave radio. For example, “Nishi No Kaze Hare [West Wind Clear]” repeated twice in the middle and twice at the end of the daily Japanese-language short-wave voice news broadcast meant Japan-Great Britain relations were in danger. The phrase “East Wind Rain” signaled damage to U.S. relations. The U.S. intercepted and decrypted the late-November 1941 messages giving these meanings and instructions—as had Great Britain and Australia. Allied monitoring stations were then tasked to search for and monitor any messages bearing these phrases.

Many scholars and researchers have been skeptical or critical of the various revisionist or conspiracist claims revolving around the eventual Winds execute message. Some suggest that the claims are based on a selective reading of testimony and evidence that subsequently surfaced (eight investigations into the Pearl Harbor attacks ensued, from 1942 to 1946). Hanyok and Mowry thought this material might allow them “to examine important aspects of the Winds message story in a deeper fashion than before.”

Battleship Row, where the most damage occurred during the attack on Pearl Harbor.

On December 7 in Hawaii, at 1:32 pm, Honolulu time, five and a half hours after the attacks began, a monitoring station on Hawaii heard a Japanese-language news broadcast from Tokyo breathlessly describing the day’s attacks by Japanese forces, including a “death-defying raid upon the American naval and air strength in the Hawaiian area.” The announcer then interrupted with a weather report: “West Wind Clear” (relations with Great Britain are in danger). He repeated the phrase and did so twice more at the end of the program. This Winds execute message was also monitored at Portland, Oregon, at 7:02 pm, Eastern Time. It also was: “West Wind Clear.” Again, this was hours after the attack. The code phrase referencing relations with the United States was absent from these messages.

Hanyok and Mowry conclude that the Winds message was neither actionable intelligence nor a useful war warning. “A Winds Execute message was sent on 7 December, 1941,” the authors say. “The weight of the evidence indicates that one coded phrase, ‘West Wind Clear,’ was broadcast according to previous instructions some six to seven hours after the attack on Pearl Harbor.” They say it is possible that a British site may have heard a broadcast one to two hours after the attack, “but this only substantiates the anticlimatic nature of the broadcast” (p. 88).

Inside the shrine room of the USS Arizona memorial in Pearl Harbor.

“From a military standpoint, the Winds coded message contained no actionable intelligence either about the Japanese operations in Southeast Asia and absolutely nothing about Pearl Harbor. In reality, the Japanese broadcast the coded phrase(s) long after hostilities began—useless, in fact, to all who might have heard it.”

They further find that the controversy was in fact an artificial one, pumped up by misunderstandings and the imaginings of one of the key participants, whose narratives “ranged so far from the documentary evidence and the memories of all the other participants that it was completely detached from actual events.” And they say revisionist and conspiratorial writers since then have further strayed from the documented truth.

“There simply was not one shred of actionable intelligence in any of the messages or transmissions that pointed to the attack on Pearl Harbor” (p.95).

The “primary, and almost exclusive, source fueling these claims of a conspiracy surrounding the Winds message,” say the authors, was Captain Laurance Frye Safford, the founder and first commander of the U.S. Navy’s code-breaking unit, OP-20-G. Safford first publicized his views in early 1944 in the Hart Inquiry, the second of the eight investigations after the attack. He repeated his story in Army Board and Navy Board investigations later that same year. He was well regarded within the cryptologic and intelligence communities and therefore taken seriously.

In their report’s final section, “The Winds Message and the Historical Process,” Hanyok and Mowry are highly critical of Safford and later conspiratorial writers.

“The ‘conspiratorial’ version of the Winds incident was solely the product of Captain Laurance Safford’s imagining of events that had occurred prior to Pearl Harbor in the Washington, D.C., offices of naval and army intelligence,” say the authors (p. 99).

“Put to the test, though, Safford’s narrative about the Execute message simply failed to stand up to cross-examination. The Joint Congressional Committee shredded Safford’s story. The committee reduced it to the collection of unsubstantiated charges that all along had been its foundation. The documentary evidence he said was available simply did not, nor did it ever, exist. In truth, Safford produced nothing upon which any further investigation could proceed.” They say the most charitable assessment of his actions was that he was “mistaken.”

The story should have ended there, the authors say. But thirty-four years after the congressional committee report in 1946, a few private scholars resurrected Safford’s allegation of a conspiracy and with it the whole Winds controversy. These writers “inverted the normal rules of evidentiary argument,” insisting that “the government had yet to disprove Safford’s charges regardless of the fact that he never had produced any evidence to substantiate them thirty-some years earlier,” say Hanyok and Mowry (p. 99).

“The scholars and researchers who championed Safford’s version of the controversy abandoned the rigorous evidentiary requirements of the historical profession in order to advance their thesis. . . .

“Safford’s case was built on mistaken deductions, reconstructed, nonexistent documents, a mutable version of events, as well as a cast of witnesses that Safford conjured up in his imagination.

“In the end, the Winds message controversy was and remains an artificial historical phenomenon. . . . The artificial controversy that grew around the Winds message never advanced historical knowledge of the events of early December 1941. In fact, the Winds controversy distracted investigations and later historical analyses from far more important issues about the attack on Pearl Harbor.” These include, the authors say, “the fundamental organizational and operational shortcomings of American cryptology” and the “arrogant dismissal by American military and naval leaders of a Japanese capability and willingness to conduct such an operation.”

“That the Winds controversy persisted over decades is more a result of the misplaced belief by some that history is controlled by conspiracy than history being the product of human folly” (p. 100).

Hanyok told the Skeptical Inquirer that if there is anything he wanted to add to his book it would have been on “Captain Safford’s reason behind his dogged persistence in pushing his conspiracy theory.” Says Hanyok: “I came across some additional material after my book was at the printer. Safford firmly believed that radio intelligence could discover what the Japanese were up to. He was absolutely certain that the intelligence that tipped off the attack on Pearl Harbor was somewhere in the files of the Navy or Army. When he could not find what he was sure existed, he began to suspect that the files had been picked. So the vague sense of conspiracy came first. Then he began to fit the ‘pieces,’ no matter how untenable they were, to the story.”

He says some “conspiracy bloggers” have already dismissed his book as the work of “court historians.” This, he says, is “a curious insult considering that I blew the whistle on the Gulf of Tonkin coverup!” Says Hanyok: “This group is so committed that they will never change their collective mind. Believing in a conspiratorial view of history is a comfortable and comforting ideology.”


  1. West Wind Clear: Cryptology and the Winds Message Controversy—A Documentary History. By Robert J. Hanyok and David P. Mowry. United States Cryptologic History, Series IV: World War II, Volume 10. Center for Cryptologic History, National Security Agency, Ft. George Meade, MD 20755-6886, 2008. The report was Hanyok’s final publication for the CCH before his retirement in August 2008 from a long career in government; Mowry died before its publication.

Kendrick Frazier

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Kendrick Frazier is editor of the Skeptical Inquirer and a fellow of the American Association for the Advancement of Science. He is editor of several anthologies, including Science Under Siege: Defending Science, Exposing Pseudoscience.