Japan surrenders and the war in Asia ends. The War Measures Act is expected to expire on 31 December 1945.

Igor Gouzenko defects.
The Cold War begins.

Mackenzie King learns of the defection. On 7 September, Gouzenko begins his debriefing at RCMP headquarters.

The cabinet enacts PC6444 under the authority of the War Measures Act.

For the first time since the war began in 1939, the War Measures Act is no longer operable in Canada. When asked in Parliament about any outstanding Orders-in-Council passed under the act, Justice Minister Louis St. Laurent “forgets” about PC6444.

An Evening Citizen editorial opposes the incorporation of parts of the War Measures Act into the National Emergency Transition Powers Act.

Drew Pearson, a popular American radio talk-show host, reveals that the Canadian government is holding a defector who has provided information on a spy ring in Canada and the United States.

Mackenzie King approves Order-in-Council PC411. The order creates a royal commission under the Inquiries Act to investigate violations of the Official Secrets Act. Supreme Court of Canada justices Roy Lindsay Kellock and Robert Taschereau are appointed to lead the commission.

The commission begins debriefing Gouzenko.

First series of arrests by the RCMP. Eleven people are detained in the RCMP’s Rockcliffe Barracks in Ottawa (another two were arrested on 16 February).

Mackenzie King makes his first public admission about the existence of a spy ring and a defector, although he refuses to name either the defector or his country of origin.

The Government of the USSR admits to spying on Canada.

Lawyers for the wives of incarcerated suspects write to the press, complaining that both they and the wives are not allowed to see the detainees.

The commission completes its first interim report.

The commission’s first interim report is released to the public. It is timed to coincide with the appearance of Gordon Lunan, Edward W. Mazerall, Kathleen Willsher, and Emma Woikin in court.

Emma Woikin pleads guilty.

Winston Churchill delivers his “iron curtain” speech in Fulton, Missouri.

The wife of one of the men whom the commission is still holding makes a public statement, accusing it of mistreating her husband.

Fred Rose, member of Parliament, is arrested.

The commission completes its second interim report.

Mackenzie King makes a speech to the House of Commons, justifying the commission’s tactics and the powers under PC6444.

Raymond Boyer, Matt S. Nightingale, and David Shugar are released by the commission and immediately arrested by the RCMP.

Fred W. Poland’s wife initiates habeas corpus proceedings to have him released.

John Bracken, leader of the Conservative Party, makes public a letter from Israel Halperin in which Halperin protests his arrest and demands to know why he is being held without charge and denied access to counsel.

Presiding over Gordon Lunan’s case, Judge James C. McRuer sets a key precedent for the spy trials. He rules that the commission’s evidence is admissible and that Lunan’s testimony can be used against him.

The commission’s third interim report is released.

The final five detainees (Eric Adams, J.S. Benning, Israel Halperin, Fred W. Poland, Durnford Smith) are released after forty-two days in prison. All five are immediately arrested and charged.

Alan Nunn May is sentenced by the British courts to ten years in prison for espionage.

Fred Rose is sentenced to six years in prison.

The commission’s final report is released.

Sam Carr is convicted, and the last of the spy trials is completed.

Igor Gouzenko, under police protection since 1945, dies near Toronto.