Operation Barbarossa, Hitler's invasion of Russia in June 1941, aimed at nothing less than a war of extermination to annihilate Soviet communism, liquidate the Jews and create Lebensraum for the German master race. But it led to the destruction of the Third Reich, and was cataclysmic for Germany with millions of men killed, wounded or registered as missing in action. It was this colossal mistake -- rather than any action in Western Europe -- that lost Hitler the Second World War.