By August 1945, with most of its major cities already in ashes from Allied firebombing, Imperial Japan was militarily helpless to do anything but resist a ground invasion of its home islands. Its fleet had been sunk, its air force shot from the sky, its armies evicted from their vast conquests. A nation that could not feed itself was cut off from all trade and entirely surrounded by enemies. American strategists, still smarting from the furious struggle of doomed Japanese on Okinawa, warned of the cost in American soldiers — some put estimates in the high six figures — should the Allies attempt to take the islands. Others wondered if such an invasion was even necessary, since their foe had neither fuel nor food. Still others — perhaps those with the ear of President Truman — thought it wise to showcase the new American weapon, developed at such great cost and in utter secrecy, to send a warning shot to a grasping, ambitious Stalin.

On August 6, 1945, a lone American plane entered the skies over Hiroshima — an industrial town of small military worth — and dropped a single bomb named “Little Boy” from a height of 2,000 feet. The atomic blast that resulted killed some 80,000 people almost instantly and caused the deaths of some 60,000 by radiation poisoning and other causes before year’s end. Lingering illnesses would claim many more; according to the city of Hiroshima, the final death toll of the bombing was 237,062.

When the first bombing failed to provoke a Japanese surrender, a second was planned for August 9. After weather conditions forced pilots to avoid the initial target city of Kokura, another American plane descended on the ancient capital of Japanese Christianity, Nagasaki, and again dropped one bomb — this one named “Fat Man.” The military targets in the town — major factories — were destroyed that day. So were 75,000 civilians; at least an equal number would die within the year.

Were such Allied air attacks war crimes? Before we decide that question, let us first be fair to the men who made the decisions to launch those attacks in a desperate attempt to end a war that had threatened their nations’ existence.

Total War

The West was engaged in a total war, one launched by enemies that scoffed at “outmoded” standards of civilized behavior. One of the key factors that drove American leaders such as Franklin Roosevelt toward a confrontation with Japan was their real moral outrage at the sickening cruelty Japan practiced in China — routinely raping and slaughtering civilians by the thousands, using Chinese (and later, Allied) prisoners as targets for bayonet practice and as “guinea pigs” on whom to test viruses for biological warfare. The barbarism of Nazi conquests, accompanied by terror bombing, genocides and the mass execution of hostages, proved a similar goad to our fitful alliance with an embattled and isolated Britain.

With these atrocities in mind, we can begin to understand why Allied leaders insisted on unconditional surrender — a policy that prolonged the war into 1945, by far its bloodiest year, and guaranteed that the Axis governments would resist to their last iota of strength — arming twelve-year-old boys in Germany with rifles they couldn’t lift, and preparing old men and peasant mothers in Japan to fight with rocks and sticks. Our two most dangerous enemies fought to the very bitter end before submitting.

Unconditional Surrender

It is true that Americans were subject, as all men are subject, to the blind ferocity of war, and tempted to answer enemy ruthlessness tit-for-tat. Niall Ferguson, in The War of the World, documents the fact that frequently Allied soldiers simply shot German or Japanese soldiers attempting to surrender. Other soldiers collected the severed ears, or boiled skulls, of their enemies; a chilling photo in Ferguson’s book shows a wartime photo of an American girl reading her soldier boyfriend’s letter from the front, perched beside the “Jap skull” he proudly sent her. Such ugly facts, along with the savagery of our bombing campaigns, led the great Catholic philosopher Elizabeth Anscombe to describe the insistence on unconditional surrender, instead of a negotiated peace with the Axis governments, as “visibly wicked” and driven by “villainous hatred.”

But that is unfair, for several important reasons. The atrocities committed by the German and Japanese regimes against civilians outside the course of combat had genuinely shocked and disgusted the leaders of Great Britain and America. The vicious irrationalism espoused by the leaders of both enemy countries; the proudly Machiavellian dishonesty of their diplomacy leading up to the war; the blatant immorality of their war aims; all these factors made it unthinkable for Allied leaders to negotiate with the existing governments of Germany or Japan and work out peace arrangements that would leave those nations’ ruling elites in power.

Neither the Germans nor the Japanese had shown the slightest inclination to bargain in good faith, or to respect the rights of the peoples they had conquered. Why should the nations they had tried and failed to conquer offer these nations’ leaders any quarter? A negotiated peace, it should be obvious, would have made trials such as were held at Nuremburg impossible. Indeed, any truce that avoided Allied occupation would have permitted the guilty powers to erase most of the evidence of their war crimes.

But the starkest goad that drove the Allies to demand unconditional surrender in the Second World War was the vivid memory of how the First World War had ended. At the moment the Kaiser’s government gave up the fight on November 11, 1918, not a single foreign soldier stood on German soil; in fact, German armies still held large swathes of Belgium and France in the west and vast chunks of former Russian territory that had been captured during the war. The harshly punitive victors’ peace imposed on Germany, which helped guarantee future conflicts over territory and reparations, could be blamed on the Social Democratic politicians who had come to power just in time to sign the one-sided Treaty of Versailles.

What is more, the military that really had lost the war could foster the myth that Germany had been “stabbed in the back” on the verge of final victory. That blatantly baseless narrative was deliberately fostered by German officers after the war — for instance, by hiring propagandists to spread it among the ranks of unemployed army veterans. One of the most gifted speakers they employed was a failed Austrian art student named Adolf Hitler.

Allied leaders were not about to make that same mistake again. They could not negotiate a peace while German armies still held France and other conquered nations and still operated extermination camps such as Auschwitz — a peace that would leave in power some slightly watered-down version of Nazi militarism, which might in ten or twenty years in turn be denounced as yet another “stab in the back.” Germany would have to be conquered, occupied, and purged. So would the murderous, almost psychotically militaristic Japan. It is impossible to blame Franklin Roosevelt, Harry Truman, or Winston Churchill for insisting on this point. Anything less would seem like masochistic appeasement.

With all that said, there were real opportunities the Allies missed, which could have shortened the war or at least spared civilian lives, and kept our own code of war-making more distinct from that of our murderous enemies. In 1944, when German officers were conspiring (with the aid of Pope Pius XII, who used Vatican couriers to transmit their messages) to kill Adolf Hitler, seize power from the Nazis and seek a separate peace with the Western Allies, they contacted British intelligence and were spurned. An internal revolt against the Nazi regime such as Claus von Stauffenberg bravely attempted really would have offered a chance at a peace with honor — and limited the westward march of Stalin’s conquering armies.

Likewise, in the Pacific, the Americans could have made it clear much earlier that they were open to leaving the Japanese emperor in power — albeit in a truncated and purely symbolic role, ruling a demilitarized Japan. The failure to communicate to Japan this willingness helped push the U.S. toward the ugly choice of either using the atomic bomb on cities or mounting a full-scale invasion against fanatical, desperate troops who had been trained to die or commit suicide before surrendering.

How Much Do Civilian Casualties Matter?

Were there other choices? Were they practical? Could we have used the atomic weapons we had developed in a less inhuman way, one that better respected Western moral norms — for instance, by preparing for an invasion of Japan and “telegraphing” where it would occur, then using our atomic bombs primarily on Japanese soldiers instead of civilians? This is not alternative history, nor are we qualified to play armchair general at the safe distance of seventy years. There may have been practical difficulties with any such alternative scenario that would have rendered it far too ineffective. What we can say with certainty is that alternative scenarios should have been seriously considered and never passed over lightly.

Limiting civilian casualties should have been at least one of the factors in choosing bomb targets, yet there is little evidence that Allied leaders even worried about the ethics of liquidating enemy citizens from the air; indeed, it appears that on this point the Allies permitted their enemies to drag them down to their level.

A decent regard for civilian lives does not imply that we should be willing to sacrifice indefinite numbers of our soldiers to avoid any and every innocent death. Commanders must balance their first concern — winning the war, with minimal losses — against the solemn duty to spare civilians wherever possible. We can never target civilians directly or intentionally, nor totally disregard the cost in civilian lives of a military victory. To do so is to let our enemies’ worst instincts infect our own morality — with consequences that may well outlive the peace.

Our conduct of the Second World War was not determined entirely by the desire to spare our soldiers’ lives. Had that been our main concern, we could have refused to invade Continental Europe at all, and spared our men such slaughters as happened at Anzio and Normandy — leaving the conquest of Hitler to Stalin’s advancing armies. Our leaders knew that a Communist-occupied Western Europe was not in America’s interest, and so were willing to spend the lives of hundreds of thousands of men to avoid it. Restricting our use of massive urban bombing in the war would also have cost soldiers’ lives. Our statesmen could have decided that such a grim sacrifice was worthwhile, both to spare the lives of noncombatants and to avoid the degrading moral effects of ruthlessly destroying civilian populations.

This article is an abridged excerpt from The Race to Save Our Century.