The allied soldiers who died in WWI did it to defend "universal values" and to reject "the selfishness of nations only looking after their own interests. Because patriotism is exactly the opposite of nationalism," French president Emmanuel Macron said at a ceremony in Paris on Sunday (11 November) marking 100 years after the end of the conflict.

The EU "defended the common good of the world," he said.

If nationalism became mainstream, it could put Europe and the wider world on a "sinister course once again that could undermine the legacy of peace we thought we had forever sealed," Macron added.

Speaking later the same day at a 'Paris Peace Forum', he said it was "uncertain" how photographs of world leaders standing together in the French capital would look in future times.

"Will it be the bright symbol of a lasting peace between nations? Or, on the contrary, the photograph of a last moment of unity, before the world sank into a new disorder?", Macron asked.

German chancellor Angela Merkel echoed the same sentiment at the forum.

"I want to speak of my concerns that are mixed in with today's commemoration, the concern that national blinders are spreading again, that actions are taken as if to simply ignore our mutual dependencies, relationships and binding ties," she said.

They spoke out amid a rise in far-right and nationalist political forces in Europe.

They also spoke in the presence of US leader Donald Trump, who has called himself a "nationalist", as well as Russian president Vladimir Putin and Turkish leader Recep Tayyip Erdogan, who espouse a far more aggressive nationalist-imperialist ideology.

Trump and Putin shook hands with Macron and Merkel and stood next to them at the main ceremony.

They all sat together at a lunch later the same day.

But Trump and Putin did not join EU and world leaders at a symbolic walk-about on the Paris streets, and Trump left before the Paris Peace Forum began.

The US leader spoke briefly at a US military cemetery, saying only that "It is our duty to preserve the civilisation they defended".

Trump had earlier tweeted that it was "very insulting" that Macron had, in an interview before the weekend, called for Europe to create its own army, before posing with Macron on Saturday for a photoshoot marked by the US leader's cold body language.

"What's important is that he participated in the ceremony and at the dinner and at the lunch ... Peace and security in Europe depend on the US, and he [Trump] knows that," Nato head Jens Stoltenberg told the Bloomberg news agency.

Poland

The same warnings on nationalist forces and the same optics of division were mirrored in Poland at the weekend.

Donald Tusk, the Polish EU Council chief, said in a speech in the city of Lodz on Saturday: "For the first time in history we have an American administration which, to put it delicately, is not very enthusiastically tuned in to a united, strong Europe".

He also spoke of a "lunatic parade" of "those ... anti-European" politicians who "are enthusiastic about Brexit, those who are more or less enthusiastic about Washington's further steps towards isolationism, those who are flirting with Vladimir Putin with increasing intensity".

Looking ahead to next year's European Parliament elections, Tusk added: "two political currents might occupy very powerful positions in that parliament: one, increasingly brown-shirted, unambiguously anti-European, looking more and more clearly towards nationalism, working against the European Union as such. The other current belongs to those who want to integrate the European Union as much as possible."

Tusk's decision to go to Poland, which marked 100 years of independence on Sunday, instead of Paris, was seen by Polish media as marking his return to domestic politics ahead of Polish elections next year.

The current Polish government has said it cherishes its EU membership.

Rhetoric

But it has also clashed with EU institutions over its meddling with the Polish judiciary and its rejection of migrants, as well as increasingly using nationalist, xenophobic, and eurosceptic rhetoric.

Polish president Andrzej Duda, prime minister Mateusz Morawiecki, and ruling party chief Jaroslaw Kaczynski led a parade of over 200,000 people through Warsaw on Sunday.

"Thank you for bringing red-and-white [Polish] flags, for being here under those colours for which our predecessors spilled their blood," Duda said in a speech.

But the sea of red-and-white flags was punctuated by the green, neo-fascist banners of the National Radical Camp (ONR), a Polish NGO, as well as by the symbols of an Italian fascist group, the Forza Nuova.

Some cars were draped with banners which said: "Islam is Enemy of Europe" and "Delete Islam".

Members of the All-Polish Youth, another far-right group, also burned the EU flag and chanted "Down with the European Union!".

Schizophrenia?

The far-right element was much less visible than on Poland's independence day last year.

But the fact the neo-fascist attendees, this time around, mingled with the Polish government-led march and with Polish military vehicles and veterans risked making it look as if they had official blessing.

"Forza Nuova are not neo-fascists, they're just nationalists," the deputy head of the ONR, Krzysztof Bosak, told Polish news agency onet.pl, defending their invitation.

He also defended the EU flag-burning, saying: "It's not surprising. Everyone knows we're not fans of the EU. Defence of Polish independence and at the same time support for an organisation [the EU] which takes away part of our independence, is political schizophrenia," he said.