Ambitious in scope and argumentation, Walter A. Skya's book raises provocative questions about the relationship between religion and nationalism; the role of ideology in inspiring and justifying acts of violence; and the resonances among Italian fascism, German national socialism, and Islamic fundamentalism. Skya navigates this difficult terrain by formulating a concept—radical Shintō ultranationalism—that, he argues, was the dominant and mass ideology of pre-WWII Japan, so much so that it explains not just the terrorist violence of the 1930s but the very nature of the Pacific War itself.

Japan's Holy War traces the evolution of “radical Shintō ultranationalism,” from the promulgation of Japan's first national constitution in 1889 to the publication of the text Kokutai no hongi (Fundamentals of the national polity) by the Ministry of Education in 1937. This focus on radical Shintō ultranationalism, or what might more conventionally be called State Shintō, is overdue in the historical scholarship on this period and leads Skya to one of the book's most compelling claims: that understandings of State Shintō changed from the late 1800s to the 1930s. The three sections of the book chronicle important shifts in how State Shintō was conceived and discussed by a handful of prominent intellectuals.

In its first phase, the constitutional scholar Hozumi Yatsuka combined Shintō ideas with the concept of the family state in order to forward a theory of an absolute monarchy that sought the “preservation of the ethnic national purity of the Japanese emperor-centered family state” (p. 70). Hozumi's vision of monarchical absolutism came into tension with Minobe Tatsukichi's “emperor-as-organ” theory of the state, which considered the parliament an organ of the state that was similar if not equal to the emperor. By juxtaposing the ideas of Hozumi and Minobe, Skya illustrates well what he considers to be the original sin of modern Japanese politics—the writing of a “flawed” and “unworkable” constitution that contained a fundamental contradiction between “sacred monarchical absolutism and secular representative democracy” (p. 131). Alongside Hozumi and Minobe, he also describes the socialist vision of Kita Ikki, if only to downplay its significance in influencing the violence of subsequent decades.

In the second phase of State Shintō, which spanned and extended beyond the Taishō period (1912–26), the profusion of mass-based politics compelled scholars such as Uesugi Shinkichi and Kakehi Katsuhiko to “capture the hearts and minds of the masses” by articulating “mass-based totalitarian ideologies” (p. 10). Both Uesugi and Kakehi sought to unite the masses with the emperor and to promote expansionism, with Uesugi supporting violence and Kakehi advocating religion and spiritual transformation as the appropriate means to these ends. Skya's treatment of these two scholars is a welcome contribution to the scholarship on prewar ideology, especially compared to the fairly well-trodden ground of the first section of the book. In sum, he illustrates persuasively the shift from “Hozumi Yatsuka's articulation of the traditional patriarchal family-state in the late Meiji period to Uesugi Shinkichi's metaphysical moral state and Kakehi's theocratic state in the post-Meiji period” (p. 216).

Where the book falters is in its attempted reach beyond intellectual history to make broader claims about religious belief and the extent to which ideology shaped and informed behavior. Nowhere is this more evident than when Skya makes arguments about “common Japanese” or “the Japanese public.” He comments, for example, that “the common Japanese was no doubt coming to feel invincible” having been “constantly bombarded with radical Shintō ultranationalist thought” (p. 292). With scant to no evidence, it is unclear how Skya might know how “common Japanese” felt. Similarly, he argues that assassinations carried out by radical Shintō ultranationalists in the 1930s were “widely popular with the Japanese public” (p. 251). This is a statement that could have been supported by an examination of primary materials, but the only evidence that Skya provides is one quotation from a British journalist, and in a chapter that is generally thin on Japanese-language sources. Exaggeration of the singular impact of ideology on behavior also rings hollow, as when the terrorism of those involved in the February 26 Incident is explained by “the Shintō faith [which] demanded that they carry out the insurrection” (p. 245). There is no meaningful consideration of the foreign policy views, military factionalism, and opinions on more equitable sharing of wealth that also informed the violent actions of these men. Skya also insinuates that radical Shintō ultranationalism helps explain “suicidal behavior” during the war, not just of military men but of civilians as well (p. 7). Yet a lengthy paragraph about kamikaze pilots does not take into account the ambivalence and complexities of motivation discussed in Emiko Ohnuki-Tierney's (2006) Kamikaze Diaries. Nor does he consider the complicated psychology behind, or social contexts of, decisions made by Japanese civilians. Indeed, the connection between behavior and ideology is tenuous, given the lack of discussion about the dissemination of ideologies or the structures and institutions that might have influenced actions.

It is also not entirely clear why State Shintō deserves such a prominent place in Skya's conception of “ultranationalism” or prewar ideologies more broadly considered. There is certainly an argument to be made that many strands of prewar thought had as a component the idea of a divine emperor, but this might be considered a widely shared similarity, rather than the central, defining aspect of various, and varied, ideologies of the prewar period. Skya might have done more to explain why the acts of political violence in the 1930s that he lists should all fall under the umbrella of radical Shintō ultranationalism. He himself notes that what he calls the “prewar Japanese radical Shintō ultranationalist movement” was “highly politically fractured” (p. 186), and it feels at moments as though he is forcing one label onto a variegated and complicated phenomenon because “there is still no commonly agreed-on name of the ideology of extreme nationalism” (p. 18).

This concept might have carried more weight if there had been a more explicit definition of terms. Skya does spell out what constituted “radical Shintō ultranationalism” (p. 19). But he might have delved into his thoughts about radicalism, how he distinguished ultranationalism from nationalism, and how he defined fundamentalism, extremism, fascism, and totalitarianism. And his conception of terrorism as “the use of violence, or the threat of violence, to achieve certain political or religious ends” seems too broad (p. 11). He also does not grapple with the question, debated among Shintōists at the time, of whether and how Shintō should be considered a religion.

Skya's suggestion that the intellectual, political, and religious contests in which radical Shintō ultranationalists were involved should be considered a kind of clash of civilizations also deserves more attention. If one can speak of a “radical Shintō ultranationalist movement and its war against the Western world” (p. 316), questions are raised about how imperial expansion into the rest of Asia and Japan's war with China fit into this framework, and what to make of right-wing Japanese affinities to Italian fascism and German national socialism. Even if radical Shintō ultranationalists at the time conceived of their struggle as one against the Western world, the historian might reflect on the ways that such views suggested a frustration with the extent to which a mythical “pure Japan” had been lost, inextricably interwoven with things Western. Somewhat puzzling, too, is the statement that “radical Shintō ultranationalists embarked on a massive campaign to purge the nation of basic features and values of the European Enlightenment: faith in reason and rational thought, intellectual freedom and curiosity, and the secularization of society” (p. 263). It is not clear whether the author is suggesting that this campaign was explicit; if not, then it is misleading to understand reason, rationality, intellectualism, and secularization as fundamentally European.

As such, the parallels that Skya draws among radical Shintō ultranationalism, German national socialism, and radical Islamic fundamentalism are welcome opportunities for comparative inquiry, but the historical contexts, relationship to and views of states, nature of political organization, and conception and place of religion might give one pause before likening prewar Japanese Shintōists, German Nazis, and members of Al Qaeda to one another (pp. 299, 311). Certainly, they all were or are “the enemy” (p. 298) from the perspective of the United States, but assertions that “radical Shintō ultranationalists and radical Islamic militants such as Al Qaida both want or wanted a ‘holy war’ against the rest of the world” (p. 311) or that a Japanese proposal to relocate Koreans and Taiwanese was “one or two steps away from a final solution such as the one the Nazis developed for the Jews” (p. 322) could have been more rigorous.

Skya has given us much to think about, contributing to our understandings of State Shintō, offering a reminder about the need for more work on prewar Japanese ideology, and urging a comparative approach to the study of political and religious ideas. The questions that he poses should be taken up by political scientists and historians alike, as they will help propel discussions about ideologies, nationalism, and violence in prewar Japan and elsewhere.