They [the wars of early modernity] were certainly not, at any rate, some sort of continuation of the “tradition” of the Crusades (the only “holy wars” in Christian history). The Crusades, after all, began as a perfectly explicable—albeit, in the event, brutal and frequently incompetent—response to tales of atrocities committed against Eastern Christians and Western Christian pilgrims by the Seljuk Turks, and to the appeals of the Byzantine emperor Alexius I (1081–1118) for military aid in resisting Seljuk aggressions in the Eastern Christian world and at the periphery of Western Christendom. When Pope Urban II (c. 1035–1099) called for the First Crusade, there was nothing insincere in the indignation with which he recited tales of Christians robbed, enslaved, and murdered, or in his dire forebodings of Christendom conquered by an enemy that had held many Christian lands and peoples in thrall for four centuries. And, in fact, a great number of the Christian nobles who answered Urban’s call were earnest, pious, and self-sacrificing men, who saw themselves as faring forth to succor the oppressed, set the bondsman free, and rescue the holy places from desecration. Unfortunately, riding the crest of the wave of enthusiasm that initiated the First Crusade, a considerable number of louts, brigands, and killers came along as well, at least for the first leg of the journey (as I shall discuss later). Thereafter, the Crusades—sporadic, limited, inconclusive, and often pointless—became at once the last great adventure of a fading warrior caste, an occasionally bloody but ultimately profitable cultural and mercantile embassy from late Western Frankish civilization to the Byzantine Christian and Islamic civilizations, and a great ferment of cultural and intellectual interaction between East and West. They were driven by high ideals and by low motives, perhaps in equal measure. But they were entirely of their time. They were episodes within a conflict between Islam and Christendom that began in the seventh century, with the rapid and brilliant Muslim conquest of vast reaches of the Christian world. They certainly had no basis in any Christian tradition of holy war. They were more truly the last gaudy flourish of Western barbarian culture, embellished by the winsome ceremonies of chivalry.
The European wars of the sixteenth and seventeenth centuries were something altogether different. They inaugurated a new age of nationalist strife and state violence, prosecuted on a scale and with a degree of ferocity without any precedent in medieval history: wars of unification, revolutions, imperial adventures, colonialism, the rebirth of chattel slavery, endless irredentism, ideologically inspired frenzies of mass murder, nationalist cults, political terrorism, world wars—in short, the entire glorious record of European politics in the aftermath of a united Christendom. Far from the secular nation-state rescuing Western humanity from the chaos and butchery of sectarian strife, those wars were the birth pangs of the modern state and its limitless license to murder. And religious allegiances, anxieties, and hatreds were used by regional princes merely as pretexts for conflicts whose causes, effects, and alliances had very little to do with faith or confessional loyalties.
Part of the enthralling promise of an age of reason was, at least at first, the prospect of a genuinely rational ethics, not bound to the local or tribal customs of this people or that, not limited to the moral precepts of any particular creed, but available to all reasoning minds regardless of culture and – when recognized – immediately compelling to the rational will.
Was there ever a more desperate fantasy than this?
We live now in the wake of the most monstrously violent century in human history, during which the secular order (on both the political right and the political left), freed from the authority of religion, showed itself willing to kill on an unprecedented scale and with an ease of conscience worse that merely depraved. If ever an age deserved to be thought an age of darkness, it is surely ours.
Ibid., p. 106