Over the last five decades, the Catholic Church has emerged as a powerful critic of war and as an advocate for its alternatives. At the same time, researchers of armed conflict have produced a considerable body of scholarship on war and its prevention. The Catholic Case against War compares these seemingly disparate lines of thought and finds a remarkable harmony between the two.
In their detailed studies of war’s nature, the historian Joanna Bourke and military psychologist Dave Grossman both arrive at the same conclusion: once you strip away the historical causes and moral justifications, war’s inescapable essence is its killing. For Bourke, it is “the characteristic act” of war, and Grossman states that “killing is what war is all about.” Describing their experience of combat, many soldiers agree. In his autobiography, U.S. Navy sniper Chris Kyle writes, “My job was killing,” and Ken Lukowiak, who fought in the British Army during the Falklands War, recalls: “We were professional soldiers, and that’s what professional soldiers do – kill people.”
And war is not merely killing, but killing at scale—the massive, organized, sustained slaughter of fellow human beings. Scroll through any online tabulation of estimated deaths per war across history, and the sheer numbers of people killed quickly become mind-numbing. It’s not just the cases we may know best—the hundreds of thousands who perished in the American Civil War, the tens of millions killed in World War I or World War II, or the third of Europe’s German-speaking population that died in the Thirty Years War. Eighth-century China’s An Lushan Revolt killed an estimated thirty-six million people, around a sixth of the world’s population at the time. The Spanish Civil War killed a half-million people, as did the U.S. seizure of the Philippines from Spain in the early twentieth century. Nine million people died in the Russian Civil War. Between one and two million people died during Bangladesh’s Independence War against Pakistan, about the same as in Afghanistan following the Soviet invasion. And the War of the Triple Alliance, fought in Paraguay in the late 1860s, killed over half that country’s entire population. The list could go on for the rest of this chapter. As Catholic teaching emphasizes, warfare is an ongoing mass assault on human life.
Among all these persons killed by war throughout human history, the majority are its innocent victims. The most obvious are civilian noncombatants, whose deaths contemporary Vatican statements so frequently condemn. While some civilians may be guilty of supporting or profiting from wars of aggression or repression, almost all noncombatants caught up wars are not responsible for starting them, do not participate in their killing, and seek only to avoid their violence. As Erasmus observed five centuries ago, “Princes wage war unscathed and their generals thrive on it, while the main flood of misfortune sweeps over the peasants and humble citizens, who have no interest in war and gave no occasion for it.” Yet killing such noncombatants is inseparable from warfare, and always has been. Dead civilians are so common and widespread in war that scholars trying to gather accurate casualty estimates for even recent conflicts struggle to do so given the sheer volume.
Sometimes killing civilians is intentional. This can be deliberate strategy—from ancient warriors’ putting entire towns to the sword, to strategic bombing in World War II that purposely targeted civilian populations—or it can be soldiers’ killing civilians for sport, an age-old practice that still flourishes today. Inuit oral traditions describe the ancient practice of raids on rival communities where the goal was to “eliminate everyone in the village one by one, going from house to house and killing them while they slept.” On a larger scale, the 1631 sack of Magdeburg, Germany saw thirty thousand residents slaughtered. Winston Churchill, as Secretary of State for War in 1920, justified using chemical weapons against civilians to put down rebellions against British colonial rule, saying “I am strongly in favor of using poison gas against uncivilized tribes.” In a letter to his wife, a German soldier describes killing Jewish children in Belarus during World War II: “Infants flew in great arcs through the air, and we shot them to pieces in flight.” One participant in the My Lai massacre, where American soldiers killed almost five hundred noncombatants, mainly women and children, recalls: “We were told to leave nothing standing. We did what we were told, regardless of whether they were civilians.” In 1998, the Taliban in Afghanistan sacked the town of Mazar-e-Sharif, spending several days torturing and killing its inhabitants, many by being locked into shipping containers to be slowly “baked alive in the desert sun.” These examples illustrate the conclusion Steven LeBlanc and Katherine Register draw, in their study of war’s origins, that “the act of massacring civilians is as ancient as war itself,” and John Keegan’s observation, in his influential A History of Warfare, that targeting civilian populations has been “standard practice” from war’s beginnings to today.
Sometimes killing noncombatants is not so much deliberate as merely indiscriminate. In such cases, warriors may not seek out civilians to kill specifically, but they also don’t bother to distinguish them from combatants either. As the popular saying dismissively puts it: “Kill them all and let God sort them out.” The history of warfare is marked by siege and blockade tactics that use hunger and disease against combatants and noncombatant alike. And indiscriminately shelling areas from distance similarly kills both. Some kinds of modern weapons are also particularly indiscriminate (as we have seen, the Vatican is especially likely to condemn these types of arms). Most obvious are weapons of mass destruction such as nuclear or biological ones. But other armaments, such as landmines and cluster munitions, also end up killing far more noncombatants than soldiers. Unexploded landmines from the Vietnam War still regularly kill civilians fifty years after its end; children are especially at risk of death in places such as Iraq, Afghanistan, and Ukraine from picking up unexploded cluster bomblets; and environmental contaminants that remain decades after wars end continue to threaten the lives of local populations around the world.
The traditional rules of war, now enshrined in treaties such as the Geneva Conventions, include prohibitions on intentionally or indiscriminately killing civilians. Wars in which one or both parties attempt in good faith to follow such rules have been the exception in human history; either the rules didn’t exist at the time, they were simply ignored, or parties paid them lip service while continuing to engage in indiscriminate killing in the name of military necessity. But even when belligerents do try to uphold rules designed to protect noncombatants in war, as many professionalized militaries do today, they can end up killing enormous numbers of civilians anyway.
(excerpted from chapter 1)