In 2003, as a lecturer in the History Department at Yale University, Andrew Preston puzzled with his students over George W. Bush's use of religious rhetoric in his execution of the war of Iraq. Was this common in American history? Or was Bush “a premodern aberration in a postmodern world?” (x). What, in fact, had been the relationship between religion and US foreign affairs? To find answers, Preston investigated over three hundred years of bellicose preachers, pious statesmen, introspective strategists, world-combing missionaries, and a host of other defenders (or at least contenders) of the faith. The result is a truly monumental survey, beautifully written and sweeping in its analysis of what Preston identifies as the two main religious impulses behind US foreign policy. American leaders have, on the one hand, frequently waged war in the name of God, wielding the so-called “sword of the spirit.” On the other hand, these same figures have sometimes conceded to the duties of Christian pacifism, carrying a “shield of faith.” Preston argues that these twin impulses have derived as much from democratic pressures from below as from the inner directives of policy elites. In searching for “religion,” then, he focusses mainly on the pronouncements of spokespeople for various religious constituencies (mostly Protestant but also Catholic and Jewish) and on the religiously inflected biographies of Presidents and other key architects of US foreign policy. His conclusion is that George W. Bush was no aberration. Most US Presidents have, in fact, “framed and justified their foreign policies in religious terms” (610).

The achievements of this book are many. Perhaps the most important, and most basic, lesson here is simply that religious flourish in US foreign affairs cannot be dismissed, as so often it is, as superficial or opportunist window dressing on an underlying structure of realist calculation. Rather, religious beliefs and social affinities have made up the very tissue of foreign-policymaking. In a democratic nation, policymakers have consistently responded, at least to some degree, to a polity that has been subdivided, at least in part, by religiously defined constituencies. Moreover, American voters and political leaders alike have regularly relied upon religiously based ethical frameworks when debating the course of diplomatic action. For a thinker such as Alfred Thayer Mahan, to take just one example, the relationship between Protestant Christianity and national greatness was so close, so intertwined, as to render any discussion of religious “justification” irrelevant. For Mahan, as for so many others, religion formed the basis for politics; one could not take the one without the other. The consequences of such thinking, however, have varied. As Preston explains, religious influences have proved “nationalist but also internationalist, exceptionalist but also cosmopolitan, nativist but also tolerant, militant but also pacifist” (4).

These insights are the result of an impressive amount of archival research laid over an astonishingly deft synthesis of two vast historiographies. Preston's second great achievement is to bring the literature of American religious history into dialogue with that of US foreign relations. His bibliography alone merits genuflection. Yet the uneven way in which these two historiographies happen to overlap lends a peculiar shape to the book's overall narrative. In general, histories of American religious life have tended to give the greatest attention to the seventeenth, eighteenth, and nineteenth centuries. Although this is beginning to change, particularly in light of the rise of the religious right, the field's still-reigning synthesis – Sydney E. Ahlstrom's 1972 A Religious History of the American People – devotes 872 of its 1,096 pages to developments prior to 1914. Most histories of US foreign relations, by contrast, focus primarily on the twentieth century. Many do not even begin before 1898. The result, for Preston, is a line of analysis that disjoints sometime during the administration of Woodrow Wilson – or around page 233 out of 613.

The relatively open, uncrowded nature of pre-twentieth-century diplomatic narratives, combined with the rich secondary literature on early American religion, allows Preston to make some of his most innovative and surprising discoveries in the first third of his book. It is here that he delivers most powerfully on his promises, made in the Introduction, to meld the history of US foreign policy with the broader study of foreign relations, and to blend the methods of diplomatic history with those taken up by cultural, intellectual, and social historians. In Part I, through Preston's careful reading of the thought of Richard Hakluyt, Samuel Purchas, John Winthrop, and others, we learn how “geography and theology … combine[d] in a spiritual geopolitics of transatlantic expansion” (20). It rapidly becomes clear that Protestant England's conflicts with its Catholic European rivals in the New World cannot be understood without attention to ideas about salvation, chosenness, and defences against barbarism. So too the wars English colonists waged against their Indian neighbours, legitimated by Puritan divines as holy wars against the unfaithful. The theme of spiritual geopolitics returns with the Barbary Wars of the 1780s to 1810s. In one of the book's brief (and curiously few) discussions of Islam, Preston shows how tensions between the United States and the Barbary States were driven by popular fears of “Muslims as a satanic force” and the Ottoman Empire as a “hellish source of earthly evil” (114). Throughout these early chapters, we see the fledgling United States in a rich transnational context, its citizens preoccupied with visions of world-historical religious competition. If one removes the “religion,” the story no longer makes sense.

In contemplating any attempt to synthesize disconnected historiographies, one wonders if the basic structure of either will be fundamentally modified as a result. Preston comes closest to revisionism, perhaps, in his chapters on the mid-nineteenth century. Once again blending the study of foreign policy with that foreign relations, he subtly pivots away from the oft-told story of nineteenth-century isolationism and demonstrates how religious Americans – Protestant missionaries chief among them – led the way in transforming the United States from a provincial to a world power. According to Preston, missionaries were “internationalists” and “cosmopolitans” who “perceived the world as fundamentally interconnected much earlier than most others did” (180). Serving as a “de facto foreign service” at a time when the State Department had not yet fully professionalized, missionaries were “among the first to bring the world to Americans,” often serving “as brokers of a global cultural exchange” (191). They also tended to drag American diplomats into uncomfortable negotiations with foreign governments whenever unrest or hostile local authorities threatened their personal safety or private property. Incidents like this took place around the world, and sometimes in unexpected locations. In one of the book's most surprising and delightful passages, we learn of Mormon missionaries – a much-maligned religious minority in the context of domestic politics – winning official protection from French, German, Dutch, and Scandinavian “religious persecution” by dedicated American consuls who wanted no more than to safeguard the rights of Americans – all Americans – to practice their faith (189). The political consequences of religious affiliation, we learn, can vary depending on whether one is home or abroad.

This episode connects to two significant, and related, contributions of this section of the book. First, Preston demonstrates how religious liberty became a peculiar preoccupation of American foreign-policymakers during the last third of the nineteenth century – a theme that would carry over for the century to come, shaping the thought and conduct of Presidents from Franklin Delano Roosevelt to Barack Obama. Second, he attributes this development to the increasing diversity of American religious life in the decades either side of the Civil War. Missionaries played an important role in bringing questions of religious liberty to the attention of policymakers – but so too did millions of Catholic and Jewish immigrants. American Jews, in particular, were especially vociferous when it came to advocating for the rights of their coreligionists to travel freely and to practice their faith without risk of harassment or violence. Preston does an admirable (if somewhat too brief) job showing how Jewish advocates waged campaigns that confronted anti-Semitism both at home and abroad, while celebrating (and at times necessarily defending) the ideals of religious freedom and the separation of church and state. It is in recounting stories like this, in the first third of the book, that Preston deals most effectively with the sheer diversity of American religious life. Alongside white Protestant and Catholic missionaries and immigrant German and Russian Jews, we meet black American Christians (many of them also organized into missionary societies) who similarly strived to bring the twin gospels of Christianity and religious freedom to benighted sections of the Earth. We also learn of the contributions of the many women who made up such a large portion of the missionary movement.

Ironically, the richness of Preston's portrayal of these ecumenical “pressures from below” begins to fall away once he arrives at the twentieth-century portion of his story – that is, just at the moment when, in his telling, “the fusion of Protestant–Catholic–Jew in American civil religion” reached “its period of maturation,” as “Catholic and Jew were becoming full partners in, rather than adjuncts to, an American creed” (236). Perhaps this seemingly equal seat at the table obviates the need for a bottom-up approach, but the shift in Preston's account has more to do, I think, with the fact that the traditional architecture of twentieth-century diplomatic history – an architecture to which Preston largely adheres – leaves less room for the kind of social and cultural history necessary to bring more non-state actors into the mix. Whereas some recent scholars, such as Akira Iriye, have used attention to “cultural internationalism” as a way to displace the centrality of Cold War narratives, Preston's account of the years between World War I and Vietnam hews closely to traditional storylines of Great Power contests.Footnote ¹

The result is a decided emphasis on the intellectual biographies of great, mostly Protestant, men: Wilson, FDR, Niebuhr, Kennan, Dulles. Many of these chapters are outstanding; the sections on Niebuhr and Dulles struck this non-twentieth-century specialist as particularly enlightening. But because the viewpoints of Catholics and Jews are usually treated in brief succession following either a longer discussion of a single Protestant thinker or an overview of activities of a range of Protestant denominations, non-Protestant communities are sometimes rendered as either falsely homogeneous or inadvertently bloodless. Preston might have avoided this by applying his considerable skill as an intellectual historian to the thought of Jewish figures beyond Henry Kissinger. Departing somewhat from the “Protestant–Catholic–Jew” frame, he might also have devoted more attention to the consequences of resurgent and diversified immigration following the Immigration and Nationality Act of 1965 – asking more questions about the experiences and political contributions of the Hindus, Buddhists, Muslims, and New Age spiritualists he briefly mentions in chapter 25.

Indeed, the entire post-1960 era – which begins on page 501 out of 613 – cries out for deeper investigation. Although his publisher might protest, Preston's enviable storytelling ability could easily hold his readers' attention for at least another hundred pages. The most important payoff would be a richer exploration of the book's initial question: how can we explain and contextualize the religious rhetoric of George W. Bush? Preston shows beyond a doubt that Bush's pronouncements belong to a long tradition in US foreign policy; he persuasively notes that Bush's “strain of evangelicalism was not especially radical,” and that “his application of religious principles and rhetoric to public policy, including foreign policy, was not unusual” (610). But many readers will want a more concrete explanation of how this tradition has changed over time – and how we might compare the operation of religious worldviews in recent years with those at the turn of the twentieth century. Bush may belong to the same tradition as William McKinley and Woodrow Wilson, but are we to understand these men and their environments in the same way? Because the twentieth-century segment of Preston's story focusses so much on the Cold War, we learn a great deal about the religious justifications both for and against specific foreign policies in the context of that conflict. But compared to earlier parts of the book, Preston tells us less about the way religion informed entire ways of perceiving the world beyond American shores – and how this process might have operated differently in the twentieth century, compared to the eighteenth or nineteenth. Does the interaction of “geography and theology” continue to form a “spiritual geopolitics” in the twenty-first century? One surmises that the answer is yes. But lacking a fuller exploration of the recent cultural history of American religion – and, in particular, American engagements with Islam – it is difficult to fully understand its operation.

One final question casts a long shadow over Preston's history: the matter of exceptionalism. Time and again, religious flourishes in American foreign affairs have highlighted the special role of the United States as a beacon of liberty (and of religious liberty in particular). And countless observers – Preston among them – have commented on the “almost uniquely intimate relationship” between religion and American politics and diplomacy (4). But the book leaves open the question how exceptional the United States really is. While it feels unjust to ask a book that already does so much to do one more thing, a comparative perspective could have added additional insight in certain places. How has the religious rhetoric of American leaders been received by their counterparts abroad? Has this changed over time? And how have American expressions of religiosity in diplomacy compared to similar expressions from other world leaders? Preston observes that Winston Churchill, though operating in a different political context than did Franklin Delano Roosevelt, frequently invoked religion in his speeches and shared a “Protestant view of the world” (348). It would have been interesting to learn a bit more about how the British and American contexts compared – and to get a few more sidelights on the interaction between religion and foreign policy in other nations. Thanks to Preston's impressive research, we can see clearly that neither George W. Bush, nor FDR, nor any other American President has broken with tradition by invoking God's name in service to diplomacy. But one still wonders whether or not these American figures are an aberration in world politics. The answer to that question, I imagine, will come from one of the many studies that are sure to be inspired by this seminal, field-redefining book.

How amazing, exclaims Andrew Preston, to see “Billy Graham walking in the peacemaking footsteps of the National Council of Churches,” taking his 1962 crusade to Moscow and calling for “mutual respect and understanding between the two sides of the Cold War” (597). It is one of many instances of an outlook's having been developed and proclaimed by leaders of the liberal, ecumenical segment of Protestantism and eventually accepted by their evangelical rivals and by conservative politicians such as Ronald Reagan, who “encouraged” Graham, Preston adds, “to ignore the opposition of the State Department and most Christian conservatives” to go to Moscow. Twenty years earlier the National Council of Churches had brought upon itself a firestorm of evangelical wrath and right-wing scorn by exchanging visits with Russian Orthodox leaders in an effort to diminish Cold War tensions. But eventually the stance of the ecumenicals of the National Council of Churches did not look so wrongheaded even to a President whose most-remembered speech was an attack on “the evil empire” delivered to a convention of evangelicals.

The role of ecumenical Protestants as innovators in American foreign relations is only one of a number of engaging themes in Preston's Sword of the Spirit, Shield of Faith: Religion in American War and Diplomacy, but it is a theme that distinguishes Preston from most previous students of American diplomatic history. Another, larger episode of this sort, which Preston develops more extensively, is the emergence from a liberal Protestant matrix of the cluster of global aspirations that came to be called “Wilsonianism.” To be sure, scholars have routinely ascribed many of Woodrow Wilson's ideas to his Presbyterian background, but Preston goes well beyond Wilson's individual peculiarities to produce a striking account of how the “mainline churches,” prior to Wilson's leadership, “had already sketched out the principles that would soon be better known as Wilsonianism” (251).

These enduring but contested principles were, above all, “peace without victory, democracy promotion, self-determination,” and “cooperation through international organizations.” In a wide-ranging survey of religious periodicals, denominational conference proceedings, sermons, treatises, and the organizational buildup to the creation in 1908 of the Federal Council of Churches (which in 1950 became the National Council of Churches), Preston establishes the breadth and depth of the Protestant leadership's engagement with global affairs. He also shows how this engagement, keyed by the huge foreign missionary project of the American churches, rendered the Protestant leaders of the late nineteenth and early twentieth centuries “among the first to recognize” what would later be called “globalization.” These thinkers and activists “produced a foreign policy that was both nationalist and internationalist,” Preston (248–49) explains, creating a framework for Wilson's “Fourteen Points” and for styles of interventionism that opposed isolationist impulses during the 1920s and 1930s. Continuing this thread, Preston delivers a well-documented and convincing account of John Foster Dulles's incubation in the ecumenical Protestant conferences and commissions of the late 1930s and the World War II years. Dulles and the self-styled “realists” led by theologian Reinhold Niebuhr actually owed more to this ecumenical Protestant legacy than did the religious pacifists – inclined toward more absolutist doctrines and occasionally allied with isolationists – who are more often depicted by scholars as the main Protestant players in the foreign-policy debates of the 1930s and 1940s. The “idealistic” Protestants who supported military intervention in World War I developed the core arguments that the “Christian realists” of the World War II era used to justify the deployment of American power.

As these examples imply, among Preston's contributions is to correct the widespread impression that whenever religion has been a big factor in American foreign relations in the twentieth century, evangelical Protestantism has been the active force and ecumenical Protestantism a relatively minor one. Although most of Preston's story is compatible with T. Jeremy Gunn's Spiritual Weapons: The Cold War and the Forging of an American National Religion (2008) and William Imboden's Religion and American Foreign Policy, 1945–1960 (2008), Preston has a firmer grasp than either of those authors on the character of the rivalry between the evangelical and ecumenical wings of American Protestantism. Preston also brings to the study of the religious elements of Cold War discourse an imposing wealth of basic information about American religious history from early colonial times through the nineteenth and early twentieth centuries. Along the way Preston attends to non-Protestant components of American religiosity, devoting a subsection of many chapters to Catholics and to religious Jews, but Preston is correct to treat non-Protestants as minor players in his story simply because of the realities of demography and power.

That the United States was long run by Protestants, many of whom were reasonably serious about their faith, may seem a simple and obvious point. But its failure to inform so formidable a work as George C. Herring's From Colony to Superpower: U.S. Foreign Relations since 1776 can remind us of the point's importance. The index to this work of 1,056 pages – the state-of-the-art volume published in 2008 in the Oxford History of the United States – includes many references to Catholicism, but only two to Protestantism. After a handful of references to “religion” it adds, “see Catholicism.” Herring's massive synthesis of the history of American foreign relations is an ironic indicator of the significance of Preston's achievement: Herring manages not to mention the National Association of Evangelicals, the Federal Council of Churches, the National Council of Churches, the World Council of Churches, the Fellowship of Reconciliation, or Reinhold Niebuhr.

Preston shows that the overwhelmingly Protestant culture of the educated and empowered classes of Americans from the earliest settlement until quite recently has affected not only foreign policy, narrowly construed, but also the larger domain of foreign relations, incorporating a host of nongovernmental engagements with the peoples and states of Asia and Europe especially, but also of Africa and the western hemisphere. Preston's excellent chapters on missionaries not only confirm long-standard understandings of the connection between foreign missions and imperial expansion, but also demonstrate the frequency with which missionaries of the first half of the twentieth century identified with indigenous peoples and argued, at some risk to themselves, against the colonial and imperialist policies of the North Atlantic powers. John R. Mott, Sherwood Eddy, and E. Stanley Jones are titans of missionary history but few scholars of American foreign relations prior to Preston have attended to their activities and to their ability to mobilize political constituencies other than in the well-known instance of the Armenian question in the era of World War I. The powerful lobbying effort on behalf of a strong United Nations with a human rights component is an exemplary case that Preston analyses very effectively, yet even so good a book as Elizabeth Borgwardt's prize-winning A New Deal for the World: America's Vision for Human Rights (2005) makes no mention of the Federal Council of Churches or of its key operative, Frederick Nolde, or even of ecumenical Protestantism's greatest institutional leader of the mid-century decades, Methodist Bishop G. Bromley Oxnam. Preston's account of earlier episodes, such as “Manifest Destiny,” King Philip's War, and the American acquisition of the Philippines are less novel than his treatment of the twentieth century, but there, too, he is a reliable and readable guide to aspects of American history that are rarely integrated so effectively into diplomatic history.

If Sword of the Spirit, Shield of Faith is understood narrowly as a study of the history of religious lobbying and of the use of religion to justify foreign-policy decisions, it is a substantial, even commanding, work, pulling together an expanse of material never before collected between two covers. But Preston asks that we take his book as being more than this. His mission is to show just how “religion influenced U.S. foreign relations” (3). This mission now will surely be shared with others, because plenty of questions remain. How much did the religious considerations that Preston identifies control this or that decision made by government officials? Preston is properly cautious about this in case after case, repeatedly reminding his readers that a multitude of factors were often in play and that merely recognizing a role for religion does not settle things. One example where Preston needlessly restrains himself from offering a more decisive judgement can illuminate this desideratum.

Harry Truman was not a man of deep religious feeling, but his strongly biblical education was certainly conducive to his decision to recognize Israel in 1948. Preston makes a great deal of Truman's sentimental attachments, and calls attention also to the Protestant and Jewish lobbies that asked Truman to go against the scepticism of his own State Department, which worried about American interests in the oil-rich Arab world. Preston also acknowledges the sympathy for Jewish settlers created in Truman's mind, and in the minds of many other Americans, by awareness of the Holocaust. But Preston, while quoting Truman's famous remark that he had to answer “to hundreds of thousands” of Zionists and Zionist sympathizers but did not “have hundreds of thousands of Arabs in my constituents” (437), shies away from assessing the relative power of the influences upon Truman. Another scholar, no less sensitive than Preston to the religious context of Truman's personality and of the Jewish and Protestant lobbies to which he listened, might argue that domestic political considerations were so powerful as to downplay for Truman the strategic considerations pressed upon him by James Forrestal, George Marshall and others, regardless of Truman's fondness for the Old Testament.

Moreover, Preston presents the central issue in 1948 as a choice between strategic calculations – what indeed were American interests in the Middle East? – and religious feelings, when in fact the arguments against recognizing Israel sometimes had more of a religious trajectory, too, than Preston sufficiently acknowledges. Several of the Arab specialists within the State Department had been raised as missionary children in Lebanon and were theologically universalist in championing the Arab peoples against American ethno-religious prejudice. The ecumenical Protestant leadership was sensitive to the evils of colonialism and capable of interpreting the Balfour Declaration and its implementation as an extension of European power at a time when indigenous peoples around the globe had a strong claim for greater authority over their own lands. Among the most eloquent opponents of the recognition of Israel was the great Presbyterian ecumenist Bayard Dodge, who published his views in a scripture-quoting Reader's Digest article and who personally visited his friend Forrestal to reinforce Forrestal's opposition to the recognition of Israel. Dodge was president of the American University of Beirut and a vigorous sympathizer of Arabs whom he did not think should be pushed from their homes by Europeans and Americans unwilling to accept Jewish refugees into their own societies. Indeed, Truman understood that the Congress of the United States was not about to change immigration laws to welcome Jewish survivors of the Holocaust. So, was Truman's decision as heavily “religious” as Preston suggests? I am not convinced. This example should not deflect us from appreciating the light that Preston casts on case after case of government decision-making, but the example can remind us how great are the challenges of defining what is “religious” and of assessing its relative weight.

The border between the religious and the secular is of evident concern to the ecumenical Protestant President with whom Preston logically ends his book, Barack Obama. Preston emphasizes the continuities between Obama and previous American leaders, but misses a chance to underscore two crucial differences. While virtually all of Preston's cast of characters, non-presidential as well as presidential, have understood religion as an indispensable foundation for any ethically sound public policy, Obama, in a widely appreciated remark in his inaugural address, welcomed nonbelievers as well as believers into the circle of the American civic “we.” Moreover, in an earlier address that Preston quotes (611) for its recognition of the legitimacy of religious motivation in political action, Obama distinguished between motivation and justification in ways that most advocates of “more religion in the public square” have not. This key segment of Obama's speech is worth quoting at length:

Thus Obama invites religious believers to respect the integrity of secular space, and does so more forthrightly than any of his twentieth- and twenty-first-century predecessors, with the exception of John F. Kennedy, whose role in American religious and diplomatic history Preston handles well.

Overall, Sword of the Spirit, Shield of Faith is one of those rare volumes that can effect a real change in the way a major subfield of American history is practiced. From now on, thanks to Preston, historians of foreign relations are less likely to miss its religious, heavily Protestant matrix. Some of us may wish that American foreign relations had been carried out on a more consistently secular foundation, but projecting such wishes onto history would be a mistake.

The sheer breadth and sound delivery of Sword of the Spirit, Shield of Faith ensure that the sum of Andrew Preston's synthesis comfortably transcends its particular arguments. Preston is a gracious guide to several centuries of providence-powered foreign relations. Yet this fact should not distract readers from his ambitious effort to move the hand of US diplomatic and religious historiography alike. Ambition is especially welcome in the latter field. As Kevin Schultz and Paul Harvey have argued, “religion is everywhere in American history, but nowhere in American historiography.”Footnote ¹ Religion is especially missing from the broader scholarly syntheses that graduate students fret over during qualifying exams. Historians of religion are adept at playing the “paranoid-style” card – i.e. accusing their colleagues of a dismissive, epiphenomenal take on faith. Yet historians of American religion also share blame for the “everywhere-and-nowhere” phenomenon. Specialization can be a cozy thing, especially if one's book still receives ample citation in perfunctory paragraphs summarizing this or that inescapably religious moment in American history. Preston, who might be considered something of a fellow traveler when it comes to religious history, unfortunately invokes Richard Hofstadter's over-foiled phrase in an otherwise strong introduction. Overall, though, Preston stays on the offense in this successful effort to transcend the marginalization loop.

From the start, Sword of the Spirit, Shield of Faith adopts what might be called a hermeneutic of non-suspicion regarding the faith claims of its subjects. Preston takes the historical significance of religion for granted. Even when Preston sees fit to declare that religion was, in fact, an influence on said public figure (not just the ones who made a point of waxing pious), he does so with a light touch. This is not a revisionist work. Preston does not aspire to unseat the grand tomes of American history (religious history included), but instead synthesizes the relevant top-shelf works. Rather, Preston's point seems to be that religion was woven into phenomena that scholars have gotten away with secularizing. Whether things would have turned out differently sans God is beside the point. God, or some sort of providential inspiration, was present in the minds of the vast majority of Preston's subjects. On this front, Sword of the Sprit, Shield of Faith performs a useful service simply by stating the religious background or identity of nearly every major player in the book. Indeed, not doing so would be an act of historical anachronism. Preston warns US foreign-policy officials that they disregard religion “at their peril” (613). His book cites many examples of American officials who stressed religion to the imperilment of others. Preston generally does not dwell on the negative, however, in chapters that are brisk without being glib. Neither does he stress the hypocrisy that is part and parcel of godly politics.

Continuity is the key to Preston's narrative – although not, he insists, “the essential continuity of an unchanging history” (5). Somewhat more narrowly, then, Preston observes a continuity of religious invocation amid Americans' variegated engagements with the world. What precisely was invoked? Nothing terribly precise, alas, although therein lies not the rub, but the point. Civil religion, “Christian republicanism,” and generically Calvinist appeals to “providence” all tended to add up to a similar understanding of America's place in, and mission to, the world. (Preston offers other themes, but these were the guiding myths.) Put roughly, the civil religion of providential republicanism (which Preston more efficiently terms “nationalism”) boils down to the following: the United States is both a blessed and a burdened republic, and religion is the sustaining force of both its gifts and its duties.

These are far from paradigm-shifting memes, and they invite a kind of “can't-live-with-it–can't-live-without-it” ambivalence among students of faith in American public life. The modern use of “civil religion,” as Preston observes in an endnote, originally was an antidote for 1960s-era unraveling (619 n. 11). In a series of publications, Robert Bellah employed civil religion to describe the complex and enduring rituals, beliefs, and symbols that, from the founding of the nation onward, reflected “an understanding of the American experience in the light of ultimate and universal reality.” As Preston does not observe, the term quickly assumed conservative “God-and-country” connotations. Evangelical leftists, for example, attacked Richard Nixon and Billy Graham for worshipping the latter in the name of the former. The rightward turn of civil religion annoyed Bellah and led him to abandon the term altogether.Footnote ² In its less activist usage, however, the concept of civil religion usefully applies to phenomena ranging from inaugural addresses to the recent tradition of singing “God Bless America” during Major League Baseball's seventh-inning stretch. American civil religion, by almost any definition, is renowned for its capacious monotheism. In what remains a hegemonically Christian society, the rituals of civil religion usually feature much talk of God or providence and little talk of Jesus (with the exception of some recent inaugural prayers by evangelicals). American civil religion often is chauvinistic, but it is not particularly dogmatic – and it does have an inclusive side.

Preston cites civil religion for good reason, then. Running through his case studies are examples of a kind of civil religion of statecraft. Preston is at his best when identifying ways of relating to the world that were at once as theologically generous (to the frustration of zealous constituencies back home) as they were morally confident (to the frustration of allies, enemies, and victims alike). After all, it is difficult to conduct foreign policy without being a bit of a latitudinarian on matters religious. This might be the inevitable pragmatism of the parlor room, but Preston offers evidence that many of his subjects were true believers in their highly general forms of faith. A nation with an increasingly pluralistic electorate, two big-tent parties, and a winner-take-all system is bound to produce such elected and appointed officials. Harry Truman could not have been a fundamentalist Baptist and succeeded in a Democratic Party increasingly reliant on Catholic and Jewish voters. Even George W. Bush needed his WASP-ish connections every bit as much as he did those born-again votes. Diplomacy, like political discourse as a whole, employs a historically truncated vocabulary. Liberty, freedom, Republican, Democrat – and God.

Preston's themes work best for the modern diplomatic era that began in the late nineteenth century, when American millennialism merged with nascent superpower status. In an attempt to bridge periods, Preston awkwardly labels the Civil War “the first war of humanitarian intervention” (161). His analysis sharpens thereafter. For example, Preston explains exactly how foreign missionaries were and were not agents of the nation's expanding global footprint – an oxymoronic influence that he captures with a chapter title, “the imperialism of human rights” (175). The Spanish–American War was the first of four crusades, climaxing with the Cold War, around which Preston centers the second half of the book. The second crusade, World War I, stands as the critical pivot of faith-based foreign relations, as it birthed or reoriented modern Christian fundamentalism, liberalism, and realism. This is the heart of Preston's analysis, the part that best demonstrates his argument for the enduring sway of an “idealistic synthesis” of militant sword and missional shield (8).

Preston's approach is well suited for the biographical analyses of major public actors. To be sure, he gives detailed consideration to “the overseas efforts of private citizens, missionaries, and other nongovernmental organizations” and is always dutiful in acknowledging dissenters (6). Yet the presence and influence of domestic pressure groups are unavoidably episodic. The most influential ones found ways of conforming to, or deftly expanding, the metanarratives of civil religion. Here, advocacy for religious liberty stands as an important recurring theme. Using the biographical mode, Preston explores the potential and pitfalls of religious diplomacy. William McKinley and John Foster Dulles – Protestant reformers best remembered as sword-wielders – receive especially nuanced, even sympathetic, treatments. So does Ronald Reagan, whom Preston brands, with an intonation that escaped this reader, “Ronald the Lionheart” (574). Reagan's handling of the “Siberian Seven” – dogmatic Pentecostals, victims of Soviet repression, and fortunate precursors of Reagan's engagement with the USSR – is a fascinating case study. McKinley, Dulles, and Reagan all point to the tension at the heart of the idealistic synthesis: the fine line between crusades for peace and war. George W. Bush's invocation of faith thus appears unexceptional in more ways than one.

Yet did nothing change? As Preston surely would concede, civil religion in the post-1960s era carries with it a heightened degree of self-consciousness. As he notes, Presidents John F. Kennedy and Lyndon Johnson both employed a more restrained tone when it came to God and guns. Then came the cynical Richard Nixon, the hapless Jimmy Carter, and the strident religious right. Preston helpfully orients readers to the pre-1960s origins of these phenomena. In keeping with the titular theme of sword and shield, he is excellent in noting how “competing visions” of World War II and the early Cold War anticipated the more obvious fracturing of the 1960s (415). The ambivalence of many Protestant liberals about the “good war” is a reminder of the long shadow of the Great War. Later, Preston writes of a Cold War-era “great schism” between generally conservative “apostles of liberty” and generally liberal “apostles of progress” (467). There never was a postwar consensus, he contends, in an argument that will surprise pundits more than historians.

Latent in Preston's narrative is a major reason why historians often miss the faith factor in American foreign policy: secularization. He does not push this theme, which would qualify his emphasis on continuity. Secularization, no less than civil religion, carries with it the burden both of generality and of normativity. It is a valuable analytical tool, however, so long as historians recognize it as a departure from previous eras of faith presumption. The departure remains conspicuously incomplete, of course. Indeed, the pushback against certain forms of secularization (not to mention the pushback against the pushback) has created a potentially large nonacademic market for Preston's subject. Unsurprisingly, both the preface and the epilogue open with anecdotes of civil religion, à la George W. Bush. More intriguingly, Preston notes the deeply religious backgrounds of many doyens of postwar foreign policy, such as Dean Rusk and Robert McNamara, who, unlike Harry Truman, did not retain Sunday school understandings of faith, and, unlike Jimmy Carter, were not Sunday school teachers. They did, however, keep their forebears' sense of stewardship over American society. What was the gateway drug for a secularized civil religion of statecraft? Liberal Protestantism remains the obvious candidate, but Reinhold Niebuhr-style Christian realism stands out as well. Perhaps this is why pundits and historians alike (Preston included) cannot get enough of Niebuhr. Niebuhr, not William Sloane Coffin, became every responsible Democrat's favorite theologian. Perhaps Niebuhrian realism merits more explicit inclusion in Preston's idealistic synthesis: the sword, the shield, and the ethics of moral leadership in a fallen world.

In the American civil religion of statecraft, providence can either be God or a secularized stand-in for God. Preston addresses both, but without doing justice to the latter. Alas, this reviewer cannot do justice to the full sweep of a book in which religion is everywhere, including there. That is, Sword of the Spirit, Shield of Faith thankfully resists summation in a perfunctory paragraph about religion.

As anyone who has just read these three assessments of my book will appreciate, I am deeply indebted to the editors of the Journal of American Studies for selecting three such fair-minded, insightful, and well-informed reviewers who are also such exquisite writers. I was gratified that Ann Marie Wilson, David Hollinger, and Steven Miller all valued the chronological scope of the book and identified its main themes. Reading these generous but constructively critical reviews has been a joy. Responding to them is proving to be much more difficult, however, because the issues they raise are so perceptive.

Wilson notes that Sword of the Spirit, Shield of Faith is somewhat lopsided in that its coverage is much more detailed for the period since 1898 than for the period before. She's a specialist in the nineteenth century, so I was relieved that she found the chapters dealing with eras before 1898 to be the book's strongest. Her observation about the predominance of the twentieth century is apt, and her suspicion as to the reasons – that my primary concern is to trace a religious influence on American foreign relations rather than the other way around, and that the bulk of US diplomatic history occurs after 1898 – is exactly right. I don't regret prioritizing the twentieth century, though I appreciate Wilson's critique and think it's entirely valid. My own judgment led me to conclude that the richest historiographical rewards would be found after the Maine exploded in Havana harbor, but Wilson's review has made me seriously rethink that assumption. Paradoxically, she also feels that “the entire post-1960 era,” which already consumes a sixth of the book, “cries out for deeper investigation.” Again, she's onto something here, and in the future I think some of the most interesting work on the relationship between religion and US foreign policy will deal with this period in a much more systematic and detailed fashion than I've provided.

Wilson astutely notes the absence of Muslims, and she accurately characterizes my discussions of Islam as “brief” and “curiously few.” She then points out, also accurately, that even in my chapters on the late twentieth century, Hindus and Buddhists join Muslims in being conspicuous by their absence. This was intentional, though it does, as Wilson observes, run the risk of leaving a good deal out. Because Sword of the Spirit, Shield of Faith is a story about how Americans perceived and engaged with the wider world, it is primarily a story of Christians and Jews; indeed, until we reach the late nineteenth century, it's mostly a story about Protestants. As Hollinger notes, “Preston is correct to treat non-Protestants as minor players in his story simply because of the realities of demography and power.” Muslims, Hindus, and Buddhists have, to my knowledge, never had much of an influence on US foreign policy as Americans. Thus I decided to narrow my focus to the roles played by American religious actors. This explains why Tim LaHaye, a mediocre writer of best-selling fundamentalist pulp fiction who had no direct influence on US foreign policy, has as many index entries as Osama bin Laden and Ayatollah Ruhollah Khomeini combined.

Hollinger is one of our most perceptive observers of American religion and secularism, particularly but not only regarding the process of Jewish assimilation and the place of Protestantism in culture, society, and politics. His shrewd observations about the even more complex religious factors – which I completely missed – surrounding Harry Truman's decision to recognize the state of Israel in 1948 are a powerful example of how scholars can continue to refine our understanding of religion's role in American politics and foreign policy. Sword of the Spirit, Shield of Faith may be long, but it is not even close to being exhaustive, and I hope that other historians will be inspired by the book's suggestive limitations and go on to improve upon my offerings here. Hollinger's powerful analysis of Obama and secularism is another example of how this can be done.

Perhaps this will require a greater degree of incredulity from other historians. As Miller puts it, one of my main approaches to the subject of religion is, with apologies to Paul Ricoeur, “a hermeneutic of non-suspicion.” Whereas Ricoeur's insight was to show that great thinkers of the past, such as Marx and Freud, were original because of their ability to peer behind the curtain of received wisdom, I seem to have done something else. Yet beneath the surface, my lack of suspicion is not so different. I've also rejected conventional wisdom – in this case, the assumption that religion has been peripheral to the history of American foreign relations – and I did so because I felt that historians have been too incredulous when it comes to religion. Their hermeneutic of suspicion has either dismissed religion outright or searched for alternative meanings behind the religious views and actions of historical actors that seem, to the modern sensibility, irrational and otherwise inexplicable. Thus people of the past must have really meant something else when, for example, they invoked Scripture to explain themselves, which I see as a kind of Whiggish presentism of the worst sort. A methodology which accepts that people of the past often meant what they said, and then tries to unpack the multiple contexts that would have led them to arrive at such a meaning and such a saying, doesn't seem to be very rigorous at all; it isn't, as Miller rightly observes, all that suspicious. But I hope it's been more enlightening than the condescension in which historians have usually held religion. Miller, as a historian of American religion, doesn't find my lack of suspicion “revisionist,” but I think he'd feel rather differently had he been trained as a diplomatic and political historian, where Hofstadter's paranoid style still reigns supreme. In those fields, realist and rationalist-choice assumptions continue to predominate, and religion is still treated with nothing but suspicion. To many (most?) historians in my fields, religious rhetoric can rarely be anything more than simply rhetoric, and religious values can rarely (if ever) have causal utility in explaining political or diplomatic behavior. It's here where I thought that less suspicion and more empathy could guide my way.

Similarly, this is also why I devote less attention to another insightful critique offered by both Hollinger and Miller: the absence of secularization. This was not accidental. Nearly all works of diplomatic history – and that's what Sword of the Spirit, Shield of Faith primarily is – are inherently histories of secularism. Secularity, as Miller says, “carries with it the burden both of generality and of normativity,” but it's a burden already assumed by the vast majority of scholarship on the history of American foreign relations. I wanted to write something different, a corrective of sorts, and it's why religion prevails and secularism does not, despite their roughly equal, if endlessly complex, relationship in American politics, culture, and society.

I am sure that one day historians of American foreign relations will analyze religion and secularism with equal sensitivity, but I don't believe that day has come. In the meantime, though, at least we have these three reviews to guide our way.