How the world has historically responded to genocide

The United States and the European Union are set to impose new sanctions against Russia in retaliation for alleged war crimes in Ukraine after the discovery of civilians apparently tortured and killed as Russians retreated from towns around Kyiv.

This week, Ukrainian President Volodymyr Zelenskyy said Russia's actions amount to genocide.

Here & Now's Celeste Headlee speaks with historian Kenneth Davis, author of "Don’t Know Much About History" and most recently, "Strongman: The Rise of Five Dictators and the Fall of Democracy."