Those opening Swartz's fascinating and stimulating study of the multifaceted encounters between American evangelicals and global Christianity had better fasten their seat belts first. Swartz is taking his readers on a truly impressive tour de force through the global history of American evangelicalism from the beginning of the postwar revival in Chicago in 1945 to an outlook to Boston 2045 when nonwhite immigrant churches will clearly play a central role in the city's religious landscape. This wide scope allows him to bring to life some of the most important changes in the world of global evangelicalism which took place in the second half of the twentieth century: American evangelicals’ global outreach, which mirrored the United States’ rise to cultural, economic, and political dominance during the American Century, faced increasing challenges from religious actors from the majority world. Evangelical actors from the global South, which was rapidly decolonizing, challenged an American evangelical gospel which they saw as too closely intertwined with capitalism, individualism, and an American claim to world leadership. American evangelicals found themselves as well confronted with the explosion of the more enchanted version of Christianity expressed through global Pentecostalism at home and abroad. In this context, the theological battles over miracle healings and speaking in tongues turned into a global power struggle over the authenticity of the Christian Gospel and the authority to define the culture of evangelical faith. During these conflicts, the positions and flows of power in global evangelicalism constantly changed and clearly shifted south during the last decades. Swartz compellingly shows how American evangelical leaders today see themselves challenged over questions of morality, sexuality, and orthodoxy and how the United States themselves are increasingly perceived as a mission field in need of migrant churches breathing the fresh air of global Pentecostalism into it.

The scope of Swartz's work is ambitious and spans defining moments in the history of US evangelicalism such as the Soldier Field Rally in Chicago in 1945 and the Lausanne Conference of 1974. At Lausanne, a first confrontation took place between a Western evangelicalism and its focus on individual salvation and representatives from the majority world who advocated an evangelicalism with a stronger focus on social justice. Swartz explores a multitude of global experiences abroad and their ramifications at home: American evangelist Stanley Jones's growing commitment to interracial dialogue and desegregation, for example, took shape in an Indian Christian ashram in the 1950s. American evangelical missionaries working against human trafficking in Vietnam in 2017 were forced to reflect on their previous assumptions about poverty, morality, and female agency. Finally, Swartz explores the very recent conflicts between East African questionings of American morality and spirituality. Swartz's approach, through focussed case studies, works especially well because important protagonists in his narrative, such as the Korean founder of World Vision Kyung-Chik Han, keep reappearing. The same is the case for important themes and conflict lines in global evangelicalism: outcomes from the Lausanne conference, such as a commitment to a more “culturally sensitive missiology,” are explored later in the context of World Vision's cultural and political shift in organizing and running its development aid programmes using the example of the Filipino island of Occidental Mindoro in the early 1980s.

Swartz's book makes a refreshing and significant contribution to the burgeoning field of the global history of US evangelicalism. It fundamentally challenges our understanding of what makes America exceptional in terms of religious life at home and in missions abroad. Our view of American evangelicalism becomes much more complex when accepting the important Korean roots of the American international powerhouse World Vision and when seeing the Christian nation through the eyes of African Pentecostal Christians. Swartz has also written an important book about agency in the way he portrays Christians from the majority world as leaders in their own right and as independent actors following their very own understandings of the authenticity of faith and of moral norms which many in the West consider universal. It is, however, one of the shortcomings of Swartz's book that he does not invest more in tracing female agency in the world of global evangelicalism. Female actors run through Swartz's narrative, but especially in the more historical parts they are overshadowed by white men such as Billy Graham and Bob Pierce. The more contemporary parts show their involvement, for example, in the discussions over sexuality in the global Anglican Church or highlight their work against human trafficking, but future research should explore further how the changing racial hierarchies in the global world of evangelicalism are intertwined with questions of gender.

Swartz's book is thoroughly researched, firmly grounded in the historiography, and genuinely stimulating in his depth and breadth of argument. Its importance will be further demonstrated in future years when researchers around the world will look further into what American evangelicals looked for and what they learnt when facing West.