Protestants Abroad tells an epic story. In a series of case studies, roughly chronologically ordered, Hollinger explores overseas missionaries’ impact on American public life. He moves, for example, from the conflicted lives of “mish kids,” to theologians’ wrestling with the absoluteness of Christianity, to debates over America's role in the Middle East, to the confrontation with anti-Japanese prejudice, to the establishment of formidable centers for the academic study of Asian history, and finally to missionary-related forerunners of the civil rights struggle.

Protestants Abroad is a monumental achievement. The most conspicuous feature is the breadth of the research. Hollinger seems to have read every relevant primary and secondary text he could find. The book is monumental is a second way. It sets a benchmark for the clarity of its prose. In a subject that easily could fall into the linguistic mire of post-colonialist theorizing, Protestants Abroad captures the gold trophy for being informative to academic specialists and to the broader reading public at the same time.

The book is monumental in a third way, and that is the forcefulness and persuasiveness of its argument. Hollinger contends that modern US history—especially the decades stretching from the 1930s through the 1960s—is helpfully examined by viewing it through the lens of missionary history. He focuses not on the missionary experience abroad but on its “boomerang” impact on the senders themselves. That impact, he argues, proved enormously consequential for sensitizing American attitudes toward other cultures, both overseas and at home. He calls it “missionary cosmopolitanism.”

The boomerang effect expressed itself in multiple ways. Most fundamentally it prompted multitudes to recognize the radical equality of all humans, no matter their social or cultural or geographic location. This recognition originated in Christ's admonition to preach the gospel to all nations, as well as to feed the hungry, clothe the naked, and house the homeless, wherever lived. In time these universalizing biblical themes were powerfully buttressed, though also often displaced, by the knowledge of other world religions and by the cultural ramifications of global economic and military expansion.

And so it was that the missionary enterprise stimulated rank and file Americans to appreciate other people in their own terms. Before and during World War II, for example, returned missionaries, and especially their children, pressed other Americans insistently to ask, how did the Japanese themselves see the world? Or in the 1960s they pressed whites to ask, how do African Americans themselves experience the iron hand of injustice? The list goes on. Though Hollinger is not blind to the dangers of cultural imperialism, most of the changes he attributes to missionary cosmopolitanism are commonly viewed as positive, movements toward peace, reconciliation, and social justice.

Hollinger argues that individuals who, in the early twentieth century considered themselves liberals, in the mid-twentieth century mainliners, and late twentieth century ecumenists, constituted the principal carriers of missionary cosmopolitanism. They were not only well educated but often educated in the nation's most elite schools. Though socially privileged, they readily embraced America's responsibility to share the good things of American life with others less fortunate—hence the efflorescence of social gospel or social gospel-like endeavors overseas, such as schools, hospitals, and cooperatives.

The protagonists in Hollinger's story very often started their careers as more or less orthodox Protestants but soon drifted from traditional conversionist aims toward social amelioration aims. For some indeed that journey involved an explicit renunciation of the old gods in favor of new ones. Paul, Augustine, and Luther yielded to Marx, Darwin, and Freud.

A book this expertly executed deserves the honor of one or two challenges. My main reservation is that the humanitarian side of the conservative missionary enterprise gets the short end of the straw. Hollinger largely overlooks it. “What people took from the encounter,” he argues, “varied to some extent according to the mentalities they brought to it. Missionaries who went abroad with historicist and social gospel perspectives discerned features of local life less visible to missionaries rigidly programmed to see heathens and little else” (13). This packaging of the story leaves the impression that conservatives’ encounter with other cultures was so otherworldly they could do very little this-worldly good.

This is not true. Many conservatives—whether parsed as fundamentalists, premillennialists, evangelicals, confessionalists, or traditionalists—did in fact invest a big part of their lives and resources trying to redress social ills. They too dug wells, built hospitals, founded schools, confronted famine, set up orphanages, fought human trafficking, and translated the Bible and other texts into indigenous languages.

Those efforts grew from conservatives’ awareness of their shared humanity. Witness the development, especially in the mid-twentieth century, of large evangelically based humanitarian groups, such as Compassion International, Wycliffe Bible Translators, World Vision International, Samaritan's Purse, and Pew Charitable Trusts. Adventist, Mormon, and Pentecostal missions projected enduring relief endeavors of their own.

By the 1970s conservatives were also trying—albeit with mixed success—to remove the razor blades of cultural imperialism from their methods. Hollinger allows that a measure of tempering took place, but attributes it to liberal influence (85–86). Whether conservatives were emulating liberals or maturing by their own lights, the result was the same. It is telling that in 2003 Fuller Theological Seminary changed the name of its School of World Mission to the School of Intercultural Studies. That shift was more than linguistic.

To be sure, conservatives’ ultimate goal often remained individual conversion, and focused more on short-term relief than on long-term development, but in the meantime they continued to march forward, hands hard at work. They believed, as John F. Kennedy said in another context, that the task was not “to curse the darkness, but to light a candle that can guide us through the darkness.”

Missionary cosmopolitanism is hard to measure. If the criteria are public visibility, institutional power, and academic respectability, then Hollinger is undoubtedly right that it grew most often from liberal/mainline/ecumenical roots. But it grew from other roots just often enough to cast doubt on easy correlations. I think of a recent network newscast that featured a young Samaritan's Purse physician who had been posted to a West African country struggling with an Ebola outbreak. When the reporter asked the physician when she was going home, she answered simply, quietly, “I am home.”