John Keegan, whom The New York Times called "the preeminent military historian of his era," is dead. 78 years old, he died after a long illness in England, where he was born and bred. Among his 20-plus books was A History of Warfare (Alfred A. Knopf, 1993), one of the best-written and most insightful investigations of violent conflict that I've read. Keegan takes you through the entire history of war, from the ancient Greek battles chronicled by Thucydides right up through the Cold War and the First Gulf War.

Keegan's book serves as a potent counterpoint to—and more, refutation of—popular claims by scientists such as Richard Wrangham and Edward O. Wilson that war stems from deep-rooted biological impulses we share with chimpanzees. Keegan weighed and rejected these theories as well as ones attributing war to environmental and economic factors, notably overpopulation and scarcity of resources.

Although he declared war to be an "entirely masculine activity," Keegan also viewed it as cultural more than biological. As he put it, war is "always an expression of culture, often a determinant of cultural forms, in some ways the society itself." Keegan's view of war overlapped with that of Margaret Mead, who saw war as not a "biological necessity" but as an invention. War, Keegan proposed, stems primarily neither from "human nature" nor economic factors but from the "institution of war itself." War, in other words, is a self-perpetuating meme.

Evolutionary psychologists and others who favor biological theories of war cannot dismiss Keegan—as they often dismiss other critics of their stance—as a lefty peacenik postmodernist. Keegan, who came from a military family, taught at the Royal Military Academy in Sandhurst and was the military affairs editor for The Telegraph, knew far more about war than the bio-theorists do.

Keegan clearly admired many soldiers and aspects of the martial culture. But he was appalled at how immensely destructive war had become as it evolved, especially in the West. As I point out in my book, The End of War, Keegan traced the Western style of war back to the win-at-all-costs philosophy of ancient Sparta. This ruthless attitude, he suggested, combined with increasingly deadly tactics and weaponry, helped European states (and, later, the U.S.) gain control over much of the world. But Western powers also turned on each other, with catastrophic consequences.

Keegan once said that, after decades of studying World War I, he was more baffled than ever as to why it had erupted. World War I "terminated European dominance of the world and, through the suffering it inflicted on the participant populations, corrupted what was best in their civilization—its liberalism and hopefulness," he wrote. World War II "completed the ruin."

Keegan questioned the famous dictum of the Prussian statesman Carl von Clausewitz that "war is the continuation of policy by other means." The cataclysmic conflicts of the modern era, Keegan asserted, show how war can become an end in itself, pursued well past any sensible benefits for states, leaders or citizens. War's absurdity is embodied in nuclear weapons, which pose a threat to all of humanity.

Although steeped in knowledge of humanity's capacity for stupidity and cruelty, Keegan was nonetheless an optimist, who believed that we have the potential to reject the war meme once and for all. In A History of Warfare, written immediately after the Cold War and the Gulf War had ended, he cited the thesis of political scientist John Mueller that war—like human sacrifice, slavery, dueling and other noxious customs--may be vanishing.

Consider these quotes from Keegan's book: "Despite confusion and uncertainty, it seems just possible to glimpse the emerging outline of a world without war." "The effort at peace-making is motivated not by calculation of political interest but by repulsion from the spectacle of what war does."

And finally: "War, it seems to me, after a lifetime of reading about the subject, mingling with men of war, visiting the sites of war and observing its effects, may well be ceasing to commend itself to human beings as a desirable, or productive, let alone rational, means of reconciling their discontents. This is not mere idealism. Mankind does have the capacity, over time, to correlate the costs and benefits of large and universal undertakings. Throughout much of the time for which we have a record of human behavior, mankind can clearly be seen to have judged that war's benefits outweighed its costs, or appeared to do so when a putative balance was struck. Now the computation works in the opposite direction. Costs clearly exceed benefits."

Pessimists will surely dismiss Keegan's vision of a world without war as naïve. I like to think he was prescient. Read A History of Warfare and decide for yourself.

Postscript: On August 17-18, I will speak at the 2012 Kateri Tekakwitha Peace Conference near Albany, N.Y. Hope to see you there.

Photo: Wikimedia Commons.