Why did Hitler make the fateful decision to invade Poland in 1939? How did Churchill turn defeat at Dunkirk into a victory on the home front? And why did Japan\u2019s imperial designs lead to war in east Asia? In the second episode of our five-part series tackling the big questions of the Second World War, historian Laurence Rees joins Rachel Dinning to guide you through the early years of the conflict \u2013 from Pearl Harbor to the fall of Tobruk.\nLearn more about your ad choices. Visit podcastchoices.com/adchoices