Many people in the modern world are made uncomfortable by the notion of “holy war”: of wars fought in the name of religions whose central message (in the case of the major salvation religions) appears to be anti-violence. This discomfort leads some students and scholars to discount the genuineness of beliefs expressed in favor of holy war and to see religion as a mere rationalization or pretext for the real, usually material, motives they think more plausible. For example, some scholars have characterized the Crusades as western Europeans’ device for hooking into the lucrative circuits of Asian trade that had theretofore largely passed them by.
Such a view imposes modern notions of believable motivation on a different world (almost as if the Crusades were the first Gulf War) and does violence to the evidence. Not only are religious motives as we see them in the sources clearly sincere, but the best economic evidence for the Crusades is that, at the individual level, crusading was almost always a losing bet. Only Italian merchants profited consistently from crusading, and they were neither crusaders themselves nor the motivating force behind crusading.
The discomfort may stem from the difficulty of reconciling modern notions of the role of religion with aggressive war. But religion’s role as an all-encompassing worldview in the traditional world meant that it had to accommodate warfare in some way. How comfortably did it do so? A brief survey of the major salvation religions reveals a range of answers.
Buddhism conforms most closely to modern preconceptions: There is no Buddhist idea of holy war, and, although Buddhist polities have conducted warfare, the religion has legitimated war only in a limited range of cases, most notably medieval Tibet. Asoka, the first great Buddhist ruler, renounced wars of conquest on his conversion. Only in Japan, in this as in many things an exception, did a form of Buddhism, Zen, become central to the values of a warrior class. Japan and Korea also saw the rise of Buddhist warrior-monks, but in terms of the religion as a whole, they are an even greater aberration than the Zen beliefs of Japanese secular warriors, and they fought not in the name of religion but in defense of their landed estates.
Hinduism accommodated warfare early on: Warriors were one of the four major classes in the caste-bound Hindu conception of society and fulfilled their dharma, or class duty, through fighting. But the caste system that accommodated warfare also limited its legitimate scope to the warriors. A militant Hinduism did arise in response to Muslim raids and conquests, but not in any organized or centralized way, and not as a mass movement. Modern mass Hindu militancy is really a variant of nationalism, not holy war.
Islam apparently incorporated warfare into its theology from the beginning in the form of jihad, but this may be deceptive. The regular appearance of slave soldiers in a wide range of Islamic polities is a sign of discomfort at the heart of Islamic ideology with states wielding force. Islam maintains both military and spiritual interpretations of jihad, which in any case is supposed to be a defensive policy in terms of warfare. The history of Islamic holy war is further complicated by issues of conversion of nomadic peoples, fundamentalism, and, more recently, resistance to imperialism and western hegemony, in which nationalism and other modern ideologies play a large part.
Perhaps ironically, Christianity has historically made the easiest alliance with war. In contrast to Asoka’s renunciation of conquest after his conversion, Constantine, the first great Christian ruler, converted after winning a battle under the sign of the cross. The tradition of in hoc signo vinces—“in this sign you shall conquer”—became a constant part of the religion, expressed, among other ways, through the Crusades, through orders of warrior-monks unprecedented elsewhere (the Japanese monks being in truth incommensurable with the Templars and their like), and through the deep penetration into society of crusading ideals, as evidenced in events such as the Children’s Crusade. Christianity’s warlike zeal would later be turned inward in the Wars of Religion (though Islam too has had its Sunni–Shi’ite conflicts).
Two other religions are worthy of note in this context. Christianity’s accommodation with war derived in part from the Jewish notion of holy war attested in numerous biblical stories and in the Jewish revolts against Roman rule. And Zoroastrianism, like Judaism the universal-seeming religion of a particular people and state, sanctioned the state’s wars unproblematically. Indeed, Sassanid Persian warfare with the Byzantines rose to the level of a crusade on both sides at its climax around 600.
Religion, of course, was not the only factor in traditional or modern motivations to war and patterns of the use of force. But especially in the traditional world, religion should not be discounted as a sincere motivation to violence as well as to nonviolence.