Research from the United States has shown that the 9/11 terrorist attacks activated individuals’ ethnocentric predispositions to structure public opinion toward several political and social issues. Beyond this overall finding, several aspects of the activation hypothesis remain unexplored, including its geographical and substantive scope. Using the quasi-random timing of terrorist attacks during the collection of the 2016 GGSS, we demonstrate the terrorism-induced activation of ethnocentrism in Germany. Specifically, a cascade of terrorist attacks involving immigrants in the summer of 2016 activated ethnocentrism among native Germans to predict (lower) support for civil liberties relative to security concerns after its influence had been absent just a month before. Further, we show that the activation of ethnocentrism holds up in a series of robustness checks and is not explained by alternative factors, including other predispositions.