For the past two months, Sergei Lenta wakes every Saturday and preps himself to fight for what he considers a deeply righteous cause. He dons a thick coat to cope with the bitter winter weather, a red military-style beret, a white armband, and a yellow reflective safety vest and heads to the center of Paris to call for the overthrow of French Republic.

Lenta is part of the French protest that started in November as a collective outcry against higher taxes and declining social benefits. But the 29 year old is not like thousands of fellow citizens who have taken to the streets. Lenta is an ideological warrior who fought with Russian-backed paramilitaries in the eastern Ukrainian province of Donbas before bringing his militant politics back home.

“We must end the Republic and democracy,” said Lenta at a weekly demonstration in late February.

The Yellow Vest movement has revealed the deep-seated fractures of French society and mistrust of politicians like President Emmanuel Macron to fix economic problems. At the same time, the movement has become a new battleground of ideas — and possible recruiting ground for fringe Kremlin-linked groups to take advantage of the social disorder for their own ends.

Lenta and least three other members of his former Donbas battalion have inveigled themselves into the heart of the protests as self-appointed security guards. They don’t bear arms, but they do carry a sense of authority and self-importance that matches the rising tide of right-wing movements across Europe, many of which have links to Russia and share the common goal of undermining European institutions that Moscow considers enemies.

In December French officials told The Wall Street Journal that they were looking into any possible role that Russian bots or actors had in amplifying the anti-government protests. Macron’s election victory over pro-Russian candidates François Fillon and Marine Le Pen was a shock for Moscow, and Macron has since become one of Russian President Vladimir Putin’s most outspoken critics.

There is no evidence to suggest that Lenta and the Donbas militia members participating in the Yellow Vest movement are receiving financial support from Russia. But their presence on the streets of Paris has been provocative nonetheless.

In January, Lenta’s Donbas comrades were widely photographed at the Paris rally holding the flags of the Donbas breakaway republic, which is backed by Moscow but condemned as as illegal political entity by the rest of the international community.  

Government officials immediately tried to tamp fears of Russian infiltration into French politics, while also conceding that they were worried about the rise of militant ideology in the country that traditionally has been known for liberty, unity and equality. “Yes, there is this far-right/pro-Russian trend but it’s not the only one in the [Yellow Vest] movement,” said French government spokesman Benjamin Griveaux on the television program “The Great Rendezvous.”

Some French political analysts view the situation with more equanimity, saying the ex-Donbas fighters are more comical than dangerous.

“Their aim is to parade themselves and pretend to be war heroes,” said Jean-Yves Camus, an expert on the French far-right movement and director of the Observatory of Radical Policies of the Jean-Jaurès Foundation. “They live in a permanent fantasy and are constantly hoping to participate in something historically important.”

Russian and French right-wing intellectuals have historical ties to religion, nationalism and monarchism, but it’s only been since 2014 that Russia has seen these political views gain momentum in France. In that year, French political leader Marine Le Pen confirmed she had secured a €9 million ($11.1 million) loan from a niche Moscow bank, funds that helped propel her right-wing National Front party to a string of municipal election victories and more seats in the European Union parliament. At the same time, the National Front has become a leading critic of European sanctions on Russia and provided political cover for Putin’s annexation of Crimea and the war to split Donbas from Ukraine.

Lenta, an ex-French soldier and member of a banned neo-fascist French organization, was among a group of foreign right-wing activists who joined the pro-Russian separatists in Donbas in 2014 in a battalion known as the Continental Unit.

While in eastern Ukraine, Lenta spent significant time online posting about the unit’s alleged exploits, but other French volunteers, including 26-year-old student turned fighter Sergei Munier, found him too passive for their taste. “I didn’t want to join Lenta’s group because I wanted to go to the front, in the real battlefield where we were fighting every day, instead of sitting behind in the trenches,” Munier said.

In late 2018, both men found themselves reunited on the streets of Paris, along with other former Donbas fighters.

The men say they were questioned by French intelligence services when they returned from Donbas, but the French security forces have not interfered with them as Yellow Vest members.

Since January, the Donbas militia members have participated in the protests as members of the self-appointed security teams. Their job is to keep order in the ranks of demonstrators and avoid violence with the police.

With their their white armbands, earphones and communications protocols, they carry themselves with a martial sense of discipline and duty.

Both Lenta and Munier say they are participating in the protests not as members of an armed movement, but as regular French citizens — who also happen to advocate the overthrow of the democratic republic.

“I have a duty to my country. We must fight the illegitimacy of the current power,” Munier said.