"East Wind Rain"

I was going to let Pearl Harbor Day slide, uncommented, as I had nothing in particular to say about it that would add to the subject.

Then I saw this New York Times article, reproduced in today's Seattle Times.

December 7, 2008

Report Debunks Theory That the U.S. Heard a Coded Warning About Pearl Harbor By SAM ROBERTS
It has remained one of World War II’s most enduring mysteries, one that resonated decades later after Sept. 11: Who in Washington knew what and when before the Japanese attacked Pearl Harbor on Dec. 7, 1941?

Specifically, who heard or saw a transcript of a Tokyo shortwave radio news broadcast that was interrupted by a prearranged coded weather report? The weather bulletin signaled Japanese diplomats around the world to destroy confidential documents and codes because war with the United States, the Soviet Union or Britain was beginning.

In testimony for government inquiries, witnesses said that the “winds execute” message was intercepted as early as Dec. 4, three days before the attack.

But after analyzing American and foreign intelligence sources and decrypted cables, historians for the National Security Agency concluded in a documentary history released last week that whatever other warnings reached Washington about the attack, the “winds execute” message was not one of them.

A Japanese message intercepted and decoded on Nov. 19, 1941, at an American monitoring station on Bainbridge Island, in Washington State, appeared to lay out the “winds execute” situation. If diplomatic relations were “in danger” with one of three countries, a coded phrase would be repeated as a special weather bulletin twice in the middle and twice at the end of the daily Japanese-language news broadcast.

“East wind rain” would mean the United States; “north wind cloudy,” the Soviet Union; and “west wind clear,” Britain.

In the history, “West Wind Clear,” published by the agency’s Center for Cryptologic History, the authors, Robert J. Hanyok and the late David Mowry, attribute accounts of the message being broadcast to the flawed or fabricated memory of some witnesses, perhaps to deflect culpability from other officials for the United States’ insufficient readiness for war.

(more)

The NYTimes article includes links to two "exhibits" from the post-war Congressional Inquiry into the attack: A US Navy translation of the Japanese message describing the codes and the circumstances under which they will be broadcast, and how, and another translation of a Japanese message giving further instructions regarding the destruction of diplomatic codes.

The Navy translation has a hand-written note, "probably by William Friedman", saying that "...There is good evidence that “Nishi no Kazehare” was really transmitted in this way.”

Nishi No Kazare, "West Wind Clear", was the signal for war with the United Kingdom (and Thailand, Malaya, and the Dutch East Indies.)

William Friedman is sometimes known as the father of US Cryptography/Cryptanalysis. (Although he was not the first American to work in the field; after all, his own interest was sparked by an Edgar Allen Poe story!) If he says that "there is good evidence" I believe him.

Unfortunately, from the New York Times article that sparked this, it seems that the message was sent after the Pearl Harbor Attacks...