February 1940: Controlling Canadian Communications

By early 1940, Canada had set up a small network of military, R.C.M.P., and C.B.C. radio interception stations (small compared to what it would be by the end of the war). Although intercepting enemy communications coming from Germany may have been the most exciting part of Canada’s interception mission, there was another important part of Canadian signals intelligence during the Second World War, and that meant spying on other Canadians. The Canadian military was charged not only with collecting intelligence from enemies abroad, but also with preventing potentially dangerous information from making its way from Canada to Germany. To prevent the enemy from gaining intelligence that could be damaging to the Allies, it was necessary to maintain tight control over Canadian communications.

As it turned out, some of the most dangerous transmissions coming out of Canada which were intercepted in this early period of the war were broadcast from Halifax, Nova Scotia. In February 1940, Canadian authorities became aware of an enemy spy operating from Halifax, broadcasting the locations of Canadian and British ships and convoys to Germany. This kind of information in the hands of the Germans could mean the loss of Canadian and British lives due to the deadly German submarines that roamed the Atlantic—and the sinking of Allied convoys could prevent supplies from reaching Britain which were needed to sustain their war effort, and feed their people.

The Canadians had to do something to prevent these transmissions from going out.

The saga of the Halifax leaks properly began on February 1st, 1940 when the War Office in London became aware of the situation in Nova Scotia. The Canadians received the following orders from Canadian Military Headquarters in London:

(a) ORGANIZE LISTENING GERMAN BROADCASTS TO DETERMINE WHAT CANADIAN INFORMATION REACHING ENEMY SO IT CAN BE STOPPED AT SOURCE.

(b) ORGANIZE INTERCEPTION OF ILLICIT WIRELESS TRANSMISSIONS INCLUDING POSSIBLY AMERICAN AMATEUR.

(c) STRENGTHEN EXISTING MEANS FOR PREVENTING LEAKAGE OF INFORMATION ACROSS THE FRONTIER ESPECIALLY FROM PORTS.

“Proposal (b) if carried out would be most useful to the War Office apart from checking enemy intelligence originating from Canada for technical reasons explained Wethey. War Office would appreciate knowing what steps you propose taking” (CDWI00043).

(The technical reasons for wanting Canada to invest more resources into wireless interception of communications in the Western hemisphere were likely geographical: the British needed more listening posts in the Americas to supplement their own signals intelligence efforts, which were limited to geography controlled by the U.K.)

The initial reply from Ottawa was sent out that very same day, and was more than a little defensive. The Canadians assured London that they were already monitoring illegal communications, and that they were well aware of the “common gossip” that someone in Halifax was transmitting the names of outgoing ships and other information in German. As to what the Canadians could do to prevent these transmissions, Ottawa reminded London that the C.B.C. was already listening to all German language transmissions, and Canadian authorities had already implemented controls and restrictions on all long-distance forms of wired and wireless communication in Canada (CDWI00047).

The reply from the Canadian Military Headquarters in London on February 6th was polite, reassuring Ottawa that the measures being taken to control Canadian communications had been shared with the British War Office. However, London would not allow the Canadians to continue to refer to the Halifax issue as mere “gossip” and informed Ottawa that the troubling transmissions had been recorded by British personnel in January and could not be ignored (CDWI00048).

The following day, on February 7th, 1940, a letter went to the Canadian Chief of the General Staff from his Director of Military Operations and Intelligence. The issue of the Halifax “broadcasts giving the names of ships in Canadian convoys” was no longer a rumour, and had reached the very top of the Canadian military establishment. Although the C.B.C. had not reported hearing any such broadcasts, the evidence from London could not be ignored. The C.G.S. was assured that “the C.B.C. are continuing to listen to German broadcasting stations and, in co-operation with the R.C.M.P. we are continuing to try to trace any sources from which such information may be getting out of the Halifax area into enemy hands” (CDWI00051).

It is not clear from the available documents how this particular case was brought to a close, but presumably the culprit or culprits in Halifax were quickly found and dealt with, since the issue did not arise again in this file. In this early period of the war, after only a handful of months had passed since the invasion of Poland, the first challenge of Canadian signals intelligence was defensive—preventing leaks of information by controlling Canadian communications. However, this defensive mission was also intricately tied to Canada’s efforts to intercept foreign broadcasts, as we saw Britain’s additional request that Canada monitor American amateur radio traffic (for similar reasons of protecting convoys)—and we’ll get to a troublesome example of this threat on the FBI Intrigue page of this briefing book. On the next page of this briefing book, we will see how this assignment from London played out, as the Canadians spied on communications to and from New York City in the still-neutral United States of America.