After the collapse of the Soviet Union, Western politicians and commentators trumpeted the triumph of liberal democracy. Around the world, it seemed, democracy was on the march—in the former communist regimes of Eastern Europe, in large parts of Africa, and elsewhere in the developing world. Now, even the most optimistic must concede that the democratic wave has stalled and, in many places, is retreating. Voters across the globe have embraced some version of “populism” as a backlash against liberal democracy. This month we’ve invited three historians to examine the rise of nationalist populism in three countries: the United States, the Philippines, and Hungary.