Prior to World War II, Canada’s embryonic security and intelligence apparatus was limited to operations undertaken by the Royal Canadian Mounted Police (RCMP) to monitor the activities of potential subversives and to infiltrate the Canadian Communist party.
Experience acquired from the covert surveillance conducted against radicals, usually émigrés, proved helpful when, during the war, the RCMP was called upon to engage in counterespionage against Nazi spies landed by U-boat. Two good double agent cases were run with guidance from MI5, and in 1946, as the RCMP investigated leads originating from the Soviet defector Igor Gouzenko, a Special Branch was established.
The RCMP Special Branch was renamed the Directorate of Security and Intelligence in 1956, but in 1970, following the Mackenzie Commission Report, was reestablished as the RCMP Security Service. In 1984, following a royal commission conducted three years earlier by Justice David McDonald into allegations of misconduct during the Quebec crisis in 1972, the Security Service was separated from the RCMP and absorbed into a new civilian organization, the Canadian Security Intelligence Service. During the McDonald Commission hearings, it had been alleged that during the terrorist campaign conducted by the Front de Libération du Quebec (FLQ) in 1970, the RCMP had intercepted mail without warrant, burned down a barn near Montreal suspected of having been an FLQ meeting place, and burgled offices to trace the FLQ’s membership.
During World War II, Canada made a significant contribution to the Allied interception and decryption of Axis signals, and in June 1941 the Examination Unit of the National Research Council (NRC) employed the controversial American cryptographer Herbert O. Yardley to exploit enemy broadcasts that had been monitored by the Royal Canadian Signals Corps at Rockcliffe Barracks in Ottawa. Under Yardley’s supervision, the Examination Unit concentrated on Japanese broadcasts. In January 1941 he was replaced by Oliver Strachey, who had broken the Abwehr’s hand ciphers at Bletchley Park.
After the war the Examination Unit continued in its covert role as a cryptographic organization under the guise of the NRC’s Communications Branch. In 1975 it was moved to the Department of National Defence and became the Communications Security Establishment.
As a member of NATO and a party to bilateral agreements with the United States and Great Britain, Canada has played an active but not entirely reliable role in the West’s signals intelligence architecture. Prime Minister Lester Pearson’s refusal in October 1962 to allow Canadian personnel to assist the American enforcement of
the quarantine imposed on Cuba almost led to the loss of a crucial direction-finding contribution from Daniel’s Head, the Canadian wireless base in Bermuda, thereby undermining confidence in the Canadian commitment to the UKUSA partnership, which was enhanced by a separate CANUS agreement in September 1950.
During the Cold War, Canada’s other significant contribution to the intelligence community was to host two SOSUS terminals, at Massett on Queen Charlotte Island and at Shelburne, Nova Scotia.