Gouzenko affair (1945)

In September 1945, Igor Sergeievich Gouzenko, a cipher clerk in the Soviet embassy in Ottawa, defected and arrived unexpectedly at the office of Louis-Stephen St-Laurent, minister of justice, to reveal his allegations of a Soviet spy ring in Canada. From that moment Prime Minister William Lyon Mackenzie King had to face the implications of a divided world. He was too realistic to believe that Canada could isolate itself from the Cold War, but he continued to be ill at ease with the demands made on Canada for the defence of North America and western Europe. According to historians, the Gouzenko affair marks the beginning of the Cold War in Canada.