<a href="https://en.wikipedia.org/wiki/Cold_War" id="mw1g" rel="mw:WikiLink" title="Cold War">Cold War</a>: <a href="https://en.wikipedia.org/wiki/Igor_Gouzenko" id="mw1w" rel="mw:WikiLink" title="Igor Gouzenko">Igor Gouzenko</a>, a <a href="https://en.wikipedia.org/wiki/Soviet_Union" id="mw2A" rel="mw:WikiLink" title="Soviet Union">Soviet Union</a> embassy clerk, defects to Canada, exposing Soviet espionage in North America, signalling the beginning of the Cold War.