In June 1941, Hitler launched Operation Barbarossa, opening up the Eastern Front in World War II – a campaign to which more forces were committed than in any other theatre of war in history. But why did Germany invade the Soviet Union? What did Stalin and Hitler think of each other? And how did the invasion impact on Germany’s eventual defeat? To find out the answers about this escalation in the Second World War, Charlie Mills spoke to Dr. Mario Draper at the University of Kent.