This research note argues that much of the literature on support for European integration misses the heart of the nature of opposition to this process by ignoring the notion of perceived threat. Essentially, people are hostile toward the European project in great part because of their perceptions of threats posed by other cultures. I analyze this hypothesis by replicating a piece of research that previously appeared in this journal, adding measures of perceived threat to that model. The results support the main contention, which is that perceived cultural threat is an important factor that has been mistakenly ignored in explanations of hostility toward the European Union.