It is a very different matter to remember the end of the Second World War from remembering its beginning.

The beginning was a just cause, transparently so. That such a thing may occur, and occur transparently, may take us by surprise, used as we are to the moral ambiguities of cases where there is something to be said on one side and on the other. But if it may surprise us, it may also encourage us. For if the right and wrong of international situations are not, after all, always hopelessly entangled in unknown factors and rival interpretations, we know that we may place some degree of trust in our common instinct to resist evil where we see it, and find, from time to time, some better practical response to a crisis than a shrug of the shoulders. It may be possible to bear true witness to the good in forceful international action. And that encouragement sharpens our sense of responsibility. When there is a transparently just cause for resort to war, there is an obligation to resort to it. Here is something that may be demanded of us from time to time, together with the disciplines of courage and sacrifice that it involves. From the transparency of the just cause, then, we learn, or relearn, something of our vocation as human societies, and of what it may cost us to fulfil them, a hard lesson but a positive one.

But if that is what we can learn from 1939, remembering 1945 is likely to teach a more discouraging lesson. The moral clarity of vocation to resist evil can be fatally compromised by moral failure in its pursuit and execution. The “just war”, according to the old doctrine, depended not only on ius ad bellum, but on ius in bello, just conduct that respected the persons of the non-combatants and had pity on the captive defeated. Symbolically, though not in law, the end of the war occurred on August 6th 1945, eighty years to the day as I write, when atomic bombs were dropped on Japanese cities with the clear intention of destroying civilian populations – not the first, though the most dramatic and explicit, use of this strategy by the allied forces. It heralded the new era of impenetrable moral gloom and scepticism, the era of cold-war and massive deterrence, governed by terror at the total destructiveness of threat and bad conscience at the responsibility for maintaining it, into which my generation, born under the sign of August 6th, came to political adulthood.

The peace of 1945 was a bitter one, indeed, which tasted, and was subsequently conducted, more as an extension of war than as a true peace. Dietrich Bonhoeffer, who did not live to see it, had anticipated the sense of moral failure and impotence of a civilisation that would win the struggle he was engaged in, and had expressed it unforgettably: “We have been silent witnesses of evil deeds; we have been drenched by many storms; we have learned the arts of equivocation and pretence; experience has made us suspicious of others and kept us from being truthful and open; intolerable conflicts have worn us down and even made us cynical. Are we still of any use?… Will our inward powers of resistance be strong enough, and our honesty with ourselves remorseless enough, for us to find our way back to simplicity and straightforwardness?”

But here, too, when sin prevailed, grace prevailed yet more. The allies who emerged from their compromised victory remembered that the gift of God to man’s sinfulness was law, and took up the task of putting international affairs on a legal footing, developing the traditions of international law that governed the causes and conduct of war. The Geneva Conventions of 1948 and 1949, together with the even more dramatic Protocols of 1977 that founded humanitarian law, asserted the essential moral framework, derived from the traditional prohibitions of Christendom. More specialised conventions – on genocide, chemical and other indiscriminate weapons, cultural property, etc. – gave sharper focus to the general principles. This remarkable corpus, embraced in part or whole by the greater number of the world’s nations, was perhaps the most striking moral achievement of the twentieth century. Imperfect it was, of course, as all human law must be, and especially imperfect in regard to the institutions that would interpret and uphold it; yet it offered hope that, as future tyrants arose, there would be better and more coordinated ways of confronting them. Nor was this initiative ineffective; the face of war, to a degree, changed its colour. It was as a practical effect of the Protocols that weapons-research and design was reoriented from the massive destructiveness of the nuclear arsenal towards precise military targeting, a development for which an appreciative footnote, at least, is due to the late President Jimmy Carter.

Today we are confronted by a clear determination, clearer and more widespread than at any time since 1945, to set these hard-won legal achievements at defiance, a determination not on the part of the small local warlords who, surviving below the surface of international politics, were always liable to fall back upon cruelty within their means, but on the part of major powers equipped with the most advanced resources. And where we might expect the heirs of 1945, and Christians especially, to raise their voices in defence of what was gained in the sphere of international law of war, there is largely silence, sometimes acquiescent, sometimes despairing, and almost always ignorant of the extent of what was thought and done. To those who suppose themselves the heirs of the victory of 1945 this anniversary should put the sharpest of questions. Was the defeated Hitler, after all, the true victor in the realm of ideas? Have we come to admit that every effort to sustain a lawful polity among nations in conflict has come to nothing, and that unfettered exertion of will through force is the only law that merits respect in that sphere?

To remember the end of World War II with historical perspective is to remember the serious initiatives of international law it gave rise to, and to face the painful questions of what has become of them, and what is to become of them. Staged exercises in “remembering” beloved of the ceremonial classes – the journalists, the statesmen and the clergy – may serve only to help us forget the real point. I fear we shall hear a great deal of triumphant reflection on the decisions of 1939 when Britain and France declared war on Germany and (further West) 1941 when the U.S. entered the conflict, while that of August 6th 1945, with all the solemn control that it continues to exercise over our lives, may slip past unnoticed.