What happens when historians go searching for new evidence about the nation’s past? It can change the way its citizens think about their country as well as their identity. And it can upset both citizens and those who govern them. In Part 1 of this 2-part series, historian Robert Johnson looks at what happens when Russians begin to examine Stalin’s vaunted role as a leader during World War II. Part 2 – about the Vietnam War – airs on Thursday, May 2.