Poland
In reality, there was fighting long before this point, but the official beginning of WWII was when Germany invaded Poland. England and France had threatened Germany, stating that if Hitler were to invade Poland that the two would declare war on him. Hitler ignored the threat, and proceeded to invade. In response, England and France declared war on Germany.
England. Someone posted misinformation. No country has invaded England since 1066.
France and England were his goals.
Austria, Czechoslovakia, and Poland (The U.K. declared war 3 days later, after Hitler ignored a British ultimatum to leave).
Hitler canceled his plans to invade England after he considered he would not be able to fight Russia and England at the same time.
England could have easily been invaded by the Germans if Hitler had decided to invade England. He chose to invade Russia instead.
Poland.
Yes, World War 2 does justify its cause. Neville Chamberlain had said to Adolf Hitler that if you invade Poland there will be War. Of course, Hitler ignored this and England's prime minister at the time then declared war.
Avendale, Soviet Union
The Battle of Britan, the air war over England.
Hitler did not invade North Korea.