If we justify bombing by governments which say they have no alternative, do we leave it open to others to argue the same right? asks Hugo Hamilton.
Right now we are trying to enter into the mind of the suicide bomber who steps on the London Underground to take innocent lives. We are naturally horrified that there may be some logic, some fundamentalist argument thrashed out in smoky back rooms which seeks to justify this bloodshed.
Perhaps the question is best answered by our own attitude to the history of bombing. With the passing of the anniversary of Hiroshima, we return to the central issues of what was known as "moral bombing" during the second World War, and specifically the Truman decision to make use of atom bomb.
By now, most people automatically focus on the cost to innocent lives brought about by bombing. But history still seems to make an exception for the Churchill and Truman campaigns in Germany and Japan.
The "finest hour" is, of course, what helped to rescue Europe. Sixty years later, though, that historical view of "moral bombing" as just, if regrettable, may be causing more trouble to us than we had anticipated, simply because it may also be the same thinking that supplies the mandate for suicide bombing.
In Ireland, we had the same moral problem with the IRA bombing campaign which has now dramatically come to an end.
The IRA's declaration of a cessation of violence is an extraordinary achievement, unmatched by any combatants since the second World War. For the past 30 years Irish people have both vocally and silently distanced themselves from atrocities such as Enniskillen.
But there have also been what were known as "the sneaking regarders", the people who harbour a secret regard for the bombers without taking part themselves.
Max Hastings appears to be a "sneaking regarder" of Hiroshima. Writing in the Guardian, he argues that 60 years ago the world was so sick of evil that Truman had no other option but to bring a swift end to the war with a nuclear attack.
There are many arguments for and against such a position, just as many as there are about the bombing of Dresden which the historian Frederick Taylor still justifies as a strategic target.
What is clear is that the moral issues around bombing never affect the victims.
On the anniversary of the Dresden bombing, for example, the survivors held a dignified and welcoming commemoration to which they invited Taylor. The survivors normally reach an understanding with victims everywhere, such as the people of Dresden have done with their counterparts in Coventry.
The arguments around moral bombing only apply to those who carry it out. In this respect, the historians always get it wrong, because they seem to apply the logic of retrospective justification. They see the bombing of Dresden and Hiroshima as morally expedient in the face of evil.
However, by justifying them, even with a heavy head, do we not leave it open to others, such as the IRA or al-Qaeda, to argue the same right, to bomb because they have no other alternative? We cannot trade innocent lives.
Of course, we understand the horrific dilemma facing decision-makers during a war, but that is no longer the issue. The problem with the historical view of both Dresden and Hiroshima is the myth of correctness which has been created around these events. This cult of retrospective justification is an expediency in itself, by which governments seek to maintain the right to repeat this bombing.
Unlike the IRA, the British and American governments both still maintain the right to unilateral action. The myth of correctness, in effect, is what keeps the right to bomb cities on the statute books. The moral standards of the past provide the judgment which leads to Vietnam and Iraq.
The "sneaking" justification for Dresden and Hiroshima is necessary to justify contemporary policies. In other words, we are conscripting the dead to die again.
In a recent piece in the German magazine Der Spiegel, the writer and jurist Bernhard Schlink made a compelling case by forcing us to rethink the "ticking bomb" argument. Do we have the right to torture a bomber in order to save innocent lives, which also happens to be Truman's argument, saving "innocent American lives"?
Schlink confines himself to the debate surrounding a law which was being passed in Germany giving the German air force the right to shoot down a hijacked aircraft on its way to a murderous target.
Schlink argues that whatever right a fighter pilot arrogates to himself to kill innocent civilians in a split-second decision may always be argued back and forth in a court of law afterwards.
By giving him the legal right to kill civilians in advance, however, is a step too far.
Writing around the time in which the Frankfurt police chief was in the dock for threatening to torture the kidnapper of a child if he didn't reveal its whereabouts, Schlink forces us to rethink the entire moral perspective on how we see the use of force and the legal vacuum it creates.
The argument, in effect, is that human fallibility causes us to break the law, but please don't write that moral fallibility into the law. The justification of Hiroshima is the justification of a physical-force tradition. There are no exceptions.
In the early 1970s, when the IRA began its new campaign of violence in Northern Ireland and Britain, my father tried to dissuade me from ever joining or having the least sympathy for such action. Ironically, he said it was something the IRA had learned from Churchill: there was no such thing as moral bombing.
Some 30 years later, the IRA has come around to agreeing with him, but not, it seems, many historians and current policymakers who still justify Hiroshima by holding on to the moral right to bomb cities, now or in the future.
Hugo Hamilton is the author of The Speckled People (Fourth Estate)