The war in Ukraine rages on. Veteran “conflict journalist” Mstyslav Chernov captures the terror and panic of the initial assault in his stark documentary. He speaks to Westdoc about the need to be multi-lingual, surviving in a war zone, hiding the digital evidence in a tampon, which itself had to be hidden — and the universal destructiveness of war: to civilians, soldiers, and filmmakers. “20 Days in Mariupol” is in contention for an Oscar nomination and can be seen now free on Frontline and YouTube.