Igor Gouzenko was known for revealing what kind of intelligence activity in Canada?

Igor Gouzenko is primarily known for revealing the existence of Soviet spy rings operating in Canada during the early Cold War period. His defection from the Soviet Union in 1945 provided crucial evidence of a extensive network of espionage that aimed to steal classified information related to atomic research and other sensitive military and political projects. Gouzenko’s disclosures led to a major shift in public awareness regarding the extent of Soviet intelligence activities in Canada and marked the beginning of a heightened focus on espionage and security during the Cold War. This information significantly impacted Canadian politics and contributed to the wider context of anti-communist sentiment in Western nations at the time, making the revelation of Soviet spy rings the correct aspect associated with Gouzenko's legacy.