NZ Naval Intelligence warning to Americans, 6 December 1941

[rodm]

Here's an interesting nugget of intelligence provided by NZ Naval Intelligence to the Americans just prior to the Pearl Harbor attack (the message was decoded at 6 am, 6 December, American time zone).

Source: catalog.archives.gov/id/27577772

FROM: NAVOBSERVER, WELLINGTON N.Z.
ADDRESSEES: OPNAV
MESSAGE PRECEDENCE: PRIORITY - ROUTINE [note - it appears any message not marked 'routine' was transmitted with 'deferred precedence']
DATE: 6 DEC 41
TOR CODEROOM: 0605/6TH
DECODED BY: DE LA MATYR
PARAPHRASED BY: GLTUCKER

TEXT:

NEW ZEALAND NAVAL INTELLIGENCE INFORMED ME CONFIDENTIALLY, NOT FOR TRANSMISSION, THAT JAP CONSUL IN WELLINGTON HAD RECEIVED ORDERS TO DESTROY HIS CODES. A REPLY USING CODE WORD INDICATING COMPLIANCE HAS BEEN SENT TO TOKYO. ALSO THE JAP CONSOLS AT AUSTRALIA AND NEW ZEALAND HAVE BEEN DIRECTED TO FORWARD ALL POSSIBLE GEOGRAPHIC DATA. TO KEEP SOURCE AVAILABLE TO THE BRITISH, SECRECY IS DESIRED.

With hindsight, the implications of this message are clear. So, it seems NZ/British Intelligence had HUMINT inside the Japanese consulate...

Cheers

Rod

[Dave Homewood]

Very interesting.

There was so, so much evidence floating around that the Japanese were about to strike, it was even in the NZ newspapers in the weeks leading up to the attack. It annoys me when people refer to it as a 'surprise attack'. It wasn't.

[ErrolC]

Sept 12, 2021 22:30:35 GMT 12 Dave Homewood said:

Very interesting.

There was so, so much evidence floating around that the Japanese were about to strike, it was even in the NZ newspapers in the weeks leading up to the attack. It annoys me when people refer to it as a 'surprise attack'. It wasn't.

Where, when and how was a surprise. US forces throughout the Pacific were fatigued due to constant alerts and drills.

[Dave Homewood]

The how was pretty much known, as was the where. The when however was a matter of time, and not being properly prepared when an imminent outbreak of war was expected later became the theme of a major enquiry and the generals and admirals in charge were hauled over the coals.

But some like to portray the attack as totally out of the blue, unexpected and dastardly. The only surprise was the diplomats did not get the paperwork in on time to declare war before the first bombs were dropped.

[Dave Homewood]

Mark McGuire has emailed me the following:

Hi Dave

I think the source of the signal quoted in the above thread was signal interception rather than human intelligence. There is a little more about it on pages 156-157 The collectors : Naval, Army and Air Intelligence in the New Zealand Armed Forces during the Second World War (waikato.ac.nz) researchcommons.waikato.ac.nz/handle/10289/9340

Kind regards

Mark McGuire

[rodm]

Hi Dave (and Mark),

thank you for the link to a most-illuminating thesis. My initial assumption about HUMINT was because I assumed the Japanese Consulate enciphered messages using machine encryption, which I (again) assumed little 'ole NZ didn't have the facility to break...

However, my take from the thesis is that intercepted "Y" material from multiple sources was sent to the Far East Combined Bureau (FECB), Singapore, and worked on there before onward dissemination of any intelligence gained.

Page 156-157 indicates the consular message re: destroying codes was disseminated by FECB, Singapore on 2 December 1941. (original documentary source: Signal from Captain on the Staff, Singapore to DNI Admiralty, DNI Melbourne, DNI Wellington, 0905Z/2 December 1941, Suva WIT Station NA N 1 030/33/18).

Page 153 indicates the consular message re: collecting Australasian geographical data was disseminated by FECB, Singapore on 27 October 1941. (original documentary source: Captain on the Staff, Singapore to DNI Melbourne, SO(1) Wellington, DNI Admiralty, 08182Z/27 October 1941, Japanese Espionage NA EA 1 84/3/19).

Cheers

Rod