Read any history book, and it will tell you that a war began in year X, and ended in year Y. That is often just the first misleading over-simplification, from which flow others.

I was sitting on a pub patio on Friday, downing a few drinks with friends from work on the first truly warm day of the year, when somehow there arose a reference to Germany and the Germans. Somebody made a Third Reich joke, and we smiled or tittered. But two of the people present were under 30, and I wondered if they really had any context for the joke. Did the John Demjanjuk case mean anything to them? Did they even recall those over-simplified dates, 1939 to 1945? And for how much longer will people feel this information has any relevance to their lives, assuming it still does for anyone born post-1970, a quarter-century after the war’s end?

A meaningful start date for the roots of the conflict could be taken as the Versailles Peace Conference in 1919, while the final peace settlement was not signed until 1990, more than 70 years after. And given the mood of nationalism in many European countries from the mid-1800s onward, and the continued existence of Third Reich jokes like the one made on Friday, even these dates are simply markers more than definitive delineations.

Heading home Friday evening, I found myself wondering when we would put this particular conflict behind us, and what would be the significance of doing so. Perhaps it was the image of John Demjanjuk, in his eighties (though possibly faking part of his frailty), a man whose prosecution seems to accomplish very little when so many others escaped the consequences of their brutality. Assuming, that is, that he is guilty. I was reminded of Imre Finta, a Hungarian restaurateur in Toronto who faced a war-crimes trial for helping deport Hungarian Jews 20 years ago, who was convicted only to have his conviction quashed as unconstitutional. He was in his late seventies when he faced trial, and he also played the frail-old-man card convincingly. Yet he lived on into his nineties, a free citizen of Canada if a socially marked one.

I was born a few years after the end of that war, which meant my world was coloured and influenced by all that had happened during the six years of the conflict. It had gone all the way from fairly primitive tanks battling across the plains of Poland to use of the first jet-fighters and atomic weapons, and it involve tens of millions of people killed and vastly more injured, displaced and generally traumatised.

Yet even though relatively recent movies such as Schindler’s List, Saving Private Ryan and the so-so Valkyrie have kept it alive in the popular imagination, the origins and scope of the conflict and its decades of aftermath are understood by a still sizeable yet dwindling number of people. The amateur historian in me regrets this as another part of me appreciates the idea of letting the horror of it fade. The statistics on the dead in Stalingrad and Dresden, Nagasaki and Shanghai are known and recorded, and there are probably now hundreds of thousands of books written about every aspect of foreign policy and broken treaties, diplomatic blunders and failures, military errors and triumphs, the Holocaust and the Nuremberg trials, the military technology and the commanders who deployed it ... and on. Over the years I’ve read scores of them, still with some fascination yet more recently with a sense of weariness. It all seems like the film footage, which viewed today is often blotchy and blurred where, in my youth, it was pristine.

It’s expected that we must here dutifully repeat that those who forget the past are doomed to repeat it. Yet most wars are started by leaders whose immediate circle includes individuals, if not themselves, who have studied the past intently. World War II, for example, was planned and led by veterans of the prior – and quite recent – horror of 1914-1918. A frequent consequence of paying attention to military history is a desire to do it all better next time: to have the right weapons and strategy, not the wrong ones. One dangerous assumption here is usually that of high acumen on the part of the people who want to try; and it seems almost impossible to question this effectively prior to the conflict, as we found with the invasion of Iraq in 2003 and its aftermath. Waging war is forever a major consumer of treasure and lives, but it is, also, almost always an immense mistake.

No conflict since World War II has consumed quite as many lives. The tally is usually rounded out at 50-million, but could well be higher or lower. It’s legitimate to question, though, whether the TV coverage of the Vietnam War had any less of an effect on people’s thinking today than images of the misery of entire cities bombed to ruins in the 1940s. It was Pentagon policy to avoid any empathy arising for the Iraqis by controlling the flow of images coming out of Iraq, and it took last year’s conflict in Gaza to remind many people of the true destructive effects of explosives on homes and lives. That short ‘war’ (if something so lopsided can be so termed) also had the effect of, finally, almost eliminating the Holocaust as a source of sympathy and justification for Israel’s nastier actions. It thus helped further close the books on commemorating the clash of the Axis versus the Allies.

Do we gain anything by beginning the process of forgetting World War II? If it becomes like the Napoleonic wars, a source of material for historical novels or movie costume dramas (think Master and Commander, with its mawkish gesture of regret for the killing at its end), are we any better off?

The point, perhaps, is that as the Demjanjuks and Fintas die off along with the veterans and the last few Holocaust survivors, who are in their seventies or older, then the living memory is lost. That sort of memory, even though rooted in the failing minds of the elderly, creates a consciousness built around a vague guilt that we, their heirs, should do something about their sacrifices, and shape our thinking around them. We buy poppies every November, after all. But if they are gone from the world, are we also free to re-shape something new? Does the perpetuated memory of a hideous war in fact continue to prompt notions of massive violence as much as it prevents them? Can we, perhaps, only know what nightmares we still labour under when the living memory of them is gone?