When reviewing human rights throughout European history, Michael Horowitz described Jews as the “canaries in the coal mine”: nations persecuting Jews held less democratic commitment and were more likely to deny other freedoms as well. He later argued that vulnerable Christians are now the canaries, serving as a “litmus indicator of whether freedom exists not only for them – but for all others in their societies.” We expand the litmus test beyond a particular religious group to religious freedoms in general, and we agree that the violations of vulnerable religious liberties indicate potential threats to other liberties as well.

Using a wealth of new data, we have shown how denying religious freedoms so often leads to the physical abuse and displacement of individuals based on religion. But this relationship doesn't stand alone. Indeed, it is often embedded within a complex web of religious, social, ethnic, and political relationships. Religious persecution is often one part of a larger social conflict, and religious freedom is often one of many freedoms denied. The relationship between religious freedoms and persecution has implications that go far beyond the topic of religion. Later in this chapter we will briefly touch on the relationships religious freedoms hold that go beyond religious persecution and conflict. Before we introduce these relationships, however, we address a more basic question: Are religious freedoms, and religion as an issue in public life more generally, still topics in need of careful study?