Journalist Mikhail Zygar says a lot of Russian historians were actually propagandists – they worked for people in power and wrote recorded events the way politicians and elites wanted. In his new book, War and Punishment, he breaks down the historical myths he says are part of the Russian psyche, one he says Putin uses to defend the invasion of Ukraine. Zygar tells NPR's Leila Fadel that he doesn't think everyone believes the propaganda, but that it's essential to uncover the truth about the Russian empire to understand how we got to today's war, and where it might go next.