The world was sickened by images of footie thugs throwing Nazi salutes during England’s match in Sofia this week.
But the horrifying gestures and vile racism from Bulgaria fans were just a hint at the terrifying grip that far-right extremism is taking across Europe.
Underground groups are spewing hate on social media as more young people buy into nationalist ideology.
Europol warns that neo-Nazis are trying to recruit among soldiers and police who have weapons training.
It follows the rise of nationalist parties such as Italy’s Lega Nord, Alternative for Germany and the Freedom Party in Austria.
All push anti-migrant or anti-Islamic propaganda.
There were 44 arrests for foiled right-wing terror attacks last year, only 11 in 2015.
Prof Matthew Feldman of the Centre for Analysis of the Radical Right, said: “The wall between extremism and mainstream politics is now cigarette-paper-thin.”
In Germany, Nordreuz – Northern Cross – tried to get hundreds of body bags and quicklime to kill and dispose of people they see as “pro-refugee” targets.
The group, exposed in June, had close police and military links.
Even Sweden, which has welcomed refugees for decades, is witnessing more extremism with the rise of the neo-Nazi Nordic Resistance.
A far-right social network calling itself The Base is training “soldiers” at secret paramilitary-style training camps.
Anti-Jewish feeling is growing. Nazi sympathisers in Poland were filmed celebrating Hitler’s birthday by burning a huge wooden swastika.
Last week, a gunman killed two people in Halle, Germany, near a synagogue. And even in countries that saw the Third Reich’s atrocities, the alt-right is winning fans.
It is short for alternative right – a twist on far-right white nationalism that tries to present the sick ideology as a respectable intellectual movement.
Prof Feldman said: “In the Cold War there was anti-fascist consensus. The common enemy was Russia. But after the 9/11 attack there was a lot of talk in the media about Islam and the narrative began to change.
“Anti-Muslim prejudice grew. After events like the Rotherham scandal, the far-right built an ideology that all Muslims were rapists and paedophiles. This enabled it to have a social media voice.”
Michael Colborne, a journalist and far-right expert in the Balkans, says the fall of communism fuelled extremism in places such as Bulgaria.
He said: “It was a chance for nation-building in countries where nationalism had been suppressed. That brought historical revisionism and anti-communism that downplayed the dangers of fascism.”
Six men were held after the vile scenes on the terraces in Bulgaria.
Their Nazi salutes were a shock to those who believed the type of hooliganism seen here decades ago was dead.
Yet fascist groups like Combat 18 here, Scandinavia’s Nordic Resistance, Golden Dawn in Greece and Germany’s Pegida have long-running links with football thuggery.
Pavel Klymenko, of Football Against Racism in Europe, said many far-right yobs model themselves on old British groups that were the forerunners of the EDL – set up by convicted thug Tommy Robinson.
He said: “Fans are still mainly white men. The culture seen in the UK decades ago seems to be recurring. The far-right is becoming trendy and this is reflected in football.”
