World War I was promised to be the war to end all wars. The Great War was over but an even greater one was looming. In the mid 1930s war was inevitable. After Germany invaded Poland Great Britain responded by declaring war. World War II was in many ways a continuation of disputes that were left unsettled after World War I. 60 million people were killed during the years 1939 -1945 making this war the deadliest conflict in human history. What happened on the front line is what lead Britain to win World War II.