Twenty-two British D-day veterans, the youngest nearly 100, crossed the Channel on Tuesday to mark this week’s 80th anniversary of the landings in Normandy, representing a thinning thread to the heroics of two or three generations ago when about 150,000 allied soldiers began a seaborne invasion of western Europe that helped end the second world war.

Ron Hayward, a tank trooper who lost his legs fighting in France three weeks after D-day, told crowds assembled in Portsmouth on Wednesday why he and other soldiers were there: “I represent the men and women who put their lives on hold to go and fight for democracy and this country. I am here to honour their memory and their legacy, and to ensure that their story is never forgotten.”

There will not be many more opportunities to commemorate with survivors, while this time the presence of Ukraine’s president, Volodymyr Zelenskiy, in France on 6 June will be a reminder that a part of Europe is in the grip of the largest war since 1945. A deadly war also rages in Gaza, while the living memory of the second world war fades into historical record.

That D-day was a risky task is an understatement: 4,441 British, American, Canadian and other allied soldiers are estimated to have been killed on 6 June 1944, and at least a similar number of Germans. One BBC documentary, D-day: the Unheard Tapes, relying on recordings of veterans’ experiences, demonstrates how terrifying the experience was – and how nobody ought to go through it again.

Royal Marine commandos moving off the Normandy beaches during the advance inland from Sword beach. Photograph: PA/PA Archive/PA Images

“I just cried my eyes out. I just stood there and cried, I did,” James Kelly, a Royal Marines commando from Liverpool, recalled of finding himself isolated, alone in the French countryside, a few hours after he had managed to fight his way off Sword beach. A buddy had been killed in front of him as they had got to the sand, blood pumping out of his neck, but Kelly had been ordered to press on.

While leaders present at Thursday’s commemorations in Normandy – King Charles, Rishi Sunak, Joe Biden, Emmanuel Macron and Olaf Scholz – will strike appropriate notes, many of those representing forces of division will not be present, not least Vladimir Putin, the architect of the invasion on Ukraine.

On Friday, Biden is due to speak at Pointe du Hoc, where 80 years ago 225 US Rangers scaled 35-metre sheer cliffs using rope ladders shot over the top to capture a strategically situated artillery bunker. It was perhaps the most dangerous single mission on D-day, and casualties were severe. Only 90 were still able to fight when a count was taken a couple of days later.

RAF veteran Bernard Morgan,100, from Crewe, visits the war graves ahead of the Royal British Legion Service to commemorate the 80th anniversary of D-Day, at Bayeux cemetery Photograph: Getty Images

There is almost certainly another reason for the location of Biden’s address, given the US president has an election to fight. Forty years ago a Republican president, Ronald Reagan, spoke on the cliffs at the same battle site, and in front of an audience of military veterans he justified the struggle of the day in terms not obviously recognisable in Donald Trump’s Republican worldview.

“We in America have learned bitter lessons from two world wars: it is better to be here ready to protect the peace than to take blind shelter across the sea, rushing to respond only after freedom is lost,” Reagan declared – very different to Trump’s comments that he would refuse to defend Nato members who do not spend enough on defence, never mind previous threats to quit the alliance altogether.

Two years of headline news about Ukraine – but also the conflict in Gaza, so deadly for civilians, and elsewhere in the Middle East – is a reminder that there are those who appear to prefer conflict to stability. Quietly, many people are a little anxious: one recent poll, from YouGov, reports that 55% of Britons believe it is somewhat or very likely that the UK will be involved in a war in the next five years.

Since the end of the cold war at least, and perhaps since 1945, it has been easier to take stability and security in Europe for granted, helped partly by the military pact of Nato and the economic alliance of the EU, but also by the grim memory of all-out conflict. But a rise of nationalist, country-first rhetoric suggests there is also a growing carelessness. If it metastasises, as the stories of D-day survivors demonstrate, ordinary people end up bearing the brunt.