Seventy years ago today, on the night of March 9-10, 1945, about 300 American B-29 Superfortress strategic bombers dropped 1,665 tons of incendiary bombs on Tokyo. About 16 square miles (40 square kilometres) of the city was razed to the ground.  An estimated 100,000 people died and a million were left homeless. Most of them were women, children and the elderly because the men had been conscripted into military service.

The bombing pattern combined with a stiff breeze created a firestorm which turned Tokyo’s wood and paper homes into ashes. The US Air Force used napalm (invented three years before at Harvard University) and white phosporus bombs.

Kisako Motoki, then 10 years old, told Australia’s ABC News that she watched from under a bridge as the firestorm raged. Her parents and her brother were already dead:

“I saw melted burnt bodies piled up on top of each other as high as a house. I saw black pieces, bits of bodies everywhere on the ground and burnt corpses in the water. I couldn’t believe this was happening in this world.”

Yet despite the magnitude and gravity of this attack, it is not widely known let alone acknowledged, as a most egregious instance of war crimes committed against civilians under the auspices of military necessity during the Second World War.

As a child I didn’t understand why Americans were typically so incensed by the Japanese attack on Pearl Harbour that initiated the entry of those two nations into the Second World War. Sure, it was a sneak attack and thousands of American servicemen were killed, but isn’t that war? Wasn’t the naval base a legitimate target? Doesn’t it make sense to use the element of surprise when attacking your enemies?

Yet the attack on Pearl Harbour was a war crime: firstly as the opening act in a war of aggression, and secondly as an attack made without formal declaration of war or explicit warning.  We think of war crimes happening within wars, but the whole of Japan’s involvement in World War II was a crime, because wars themselves are criminal and immoral when initiated without jus ad bellum – the right to wage war.

These days we don’t seem to analyse war crimes in terms of jus ad bellum or its counterpart jus in bello – right conduct in the execution of warfare.  Instead the popular image of a war crime is heavily influenced by certain classes of action: the massacre of civilians or prisoners, the desecration of bodies, rape and pillage, as well as more ideologically driven, organised campaigns such as “ethnic cleansing” and genocide.    

The subtext of the war crimes with which we are most familiar is that they are gratuitous, unnecessary, and especially vicious; actions that make little sense from a strictly military perspective, or which do not belong in the standard array of weapons and tactics. In fact, we begin to think of war crimes primarily as crimes committed in the context of war, like the systematic rape of German civilians by the invading Soviet forces toward the end of the Second World War, the opportunistic massacre of Polish military officers by the Soviets, or the brutal and perverse mistreatment of prisoners of war by the Japanese military.

But these types of cases are by no means the sum total of war crimes or of just war theorising, it just seems that way because our attention is fixed on the examples of war crime that are easiest to identify and which we are most comfortable repudiating.  We can pick the obvious acts of opportunism and gratuitous violence, but we lose our certainty in the harder cases, as the line between legitimate act of war and war crime becomes blurred. Yet it is our ignorance – sometimes our wilful ignorance – of the rules of war and just war theory that leaves these lines more blurred than they ought to be.

We find ourselves moved and convinced by claims that firebombing civilian areas is justified on the grounds of military necessity, and indeed there is good reason to think that the destruction of Tokyo’s working class district severely inhibited the city’s industrial output.  If the firebombing had not helped the war effort it would be safe to condemn it as a gratuitous and grotesque act. But the whole point of ethics generally and the ethics of warfare in particular is that we cannot stop at the safe and simple cases of war crimes that are not useful militarily, war crimes that are easy to condemn and blame on mentally unstable, vicious, or just plain evil individuals and subcultures.

Just war theory and the rules of law do not exist simply to help us condemn bad men who do bad things for bad reasons. They are there also, and perhaps even more so, to help good men with good reasons avoid doing bad things; a task that is so much harder when we have convinced ourselves to heed only military necessity.

We cannot change the past, but we can change what we believe and think about it, and what we learn from it. Do we want the lesson of the Second World War to be that the horrific deaths of a hundred thousand people can be so easily, uncritically forgotten?

Zac Alstin is associate editor of MercatorNet. He also blogs at zacalstin.com

Zac Alstin is a writer, editor and stay-at-home dad to three marvellous children, in Adelaide, South Australia. His hobbies include martial arts, making things at home, and contemplating the underlying...