In Britain, 11 November is known as Armistice Day, but in Poland the same anniversary of the end of the first world war is remembered as Independence Day. In the west it is a memory of futile victory, but in the east it commemorates a moment of triumph, although one that would be followed by still more crushing defeat. The bright ideals of 1918 were built around a romantic conception of nationalism. Eastern Europe was to be freed from the multinational empires that had ruled it from Vienna and St Petersburg, and in their place would rise a host of little nations from Finland to Yugoslavia, to live in brotherhood and prosperity under the aegis of the League of Nations. It was a patchwork that would within 25 years disintegrate into the most terrible war – and genocide – of European history, followed by ethnic cleansings of the survivors all across eastern Europe as the old nations were reconstituted as homogenous prison camps.

The end of the second world war gave rise in the west to a very different ideal of nationhood. The European Union was built on the hope that national boundaries might become very much less salient, preserved as wrinkles on the gentle face of history rather than its fixed expression; and after the fall of the Berlin Wall it seemed that this pattern must in time spread east, even into the former Yugoslavia. If there was one lesson that every European – and not just Jewish ones – had learned from the first half of the 20th century, it was “never again”.

Never has that slogan sounded more hollow than on Saturday, when a white nationalist parade drew 60,000 people, mostly men, to Warsaw to march through the streets with most banners proclaiming “We want God” but others demanding a “White Poland”, “A holocaust for Muslims”, and “a brotherhood of white nations” – as if that had worked out after 1918. Of course, the breakdown of international order between the wars was blamed by the far right on Jews, whereas the threat now is supposed to be Muslims. But the present coalition extends to traditional antisemites, too. The organisers included groups who had been active in the antisemitic agitation of 1930s Poland, and Richard Spencer, the American neo-Nazi, had been invited, although he was kept out of the country by the merely authoritarian nationalist Law and Justice party.

Self-conscious Nazis are still a very small part of this movement. We are not seeing a straightforward return to the 1930s. But the slogans shouted today still wake disturbing echoes from 80 years ago. What we have once more is a growing cohort of men who know that the economy has no dignified use for them, and who feel this insult to their own personal self-worth is also an insult to the nation, the religion, or even the race, that they are proud to belong to. Their reaction brings shame on all three. These are dangerous emotions. When we watch these marches, we should remember the delirious enthusiasm that greeted the outbreak of the war whose ghastly end four years later we still commemorate. The hard-won common sense of each generation is easily forgotten by the children to whom it is offered as a gift. The only counter to this kind of twisted idealism is an idealism of progress and decency which can carry an equivalent meaning and urgency, but values all people for themselves, not for their race or creed.