Evangelical Protestants have had an unusually high global consciousness ever since the 19th-century blossoming of the missions movement.  For a century and a half, missionaries' support letters kept North American churchgoers aware of countries and people groups they rarely read about in newspapers. Because of connections to missionaries and relief organizations, we hear about life in places like Mozambique, Tibet, Sri Lanka, and Rwanda. And when trouble starts brewing in such places, we often hear about it through these connections first.

But while missionaries and relief workers have been a great source of global connectivity—long preceding other factors in the much-ballyhooed phenomenon of globalization—they have often been slow to engage and resist the forces of oppression in the countries where they worked. It makes sense: Missionaries and relief workers serve at the discretion of their host governments. Criticizing political leaders would imperil their ministry.

Allen Hertzke's Freeing God's Children tells the story of how evangelical Protestants in the United States moved from reluctance and ambivalence about confronting persecution to passionate engagement and action. It also tells the story of unlikely alliances—as evangelicals linked arms with Roman Catholics, Jews, secularists, and feminists to address an array of human-rights issues.

In 1995, I got a telephone call from Michael Horowitz, a former Reagan administration lawyer, who was by then installed at the conservative Hudson Institute. Horowitz, a Jew, was passionate about the plight of Christians in certain Muslim and post-Soviet era Communist countries. And the reluctance of mission agencies to speak out publicly against oppression baffled him.

 During the ...