H E SEEMS to have been a classic “lone wolf”. As far as police can tell, the man who murdered 50 worshippers, and critically wounded nine more, at two mosques in Christchurch, New Zealand on March 15th was not part of any organisation. The 28-year-old Australian, Brenton Tarrant, claimed to have developed his violent beliefs on his own, surfing the internet and visiting Europe. He bought his weapons himself. He honed his skills at a suburban shooting-range. No one there suspected that he was preparing a massacre.

Yet he was part of something much bigger. The names and slogans scrawled on his weapons were familiar to extreme white nationalists all around the world—but hardly anyone else. His ranting internet manifesto, “The Great Replacement”, repeated a staple far-right conspiracy theory: that non-white and Muslim immigrants in Western countries are invaders, ushered in by scheming elites to replace ethnic-European populations. Variants of that once-fringe idea are now common, not just in social-media posts by anonymous wackos but in the speeches of elected politicians from Hungary to Iowa.

In another sense, too, the lone wolf had a pack. Attacks by neo-Nazis, white supremacists and other extreme-right types are growing more common. In America they outnumber those committed by Islamists. Of 263 domestic terrorism incidents in 2010-17, fully 92 were carried out by far-right attackers, compared with 38 by jihadists, according to an analysis of the Global Terrorism Database by the Washington Post. In Europe jihadist killings still predominate, but deaths from extreme-right terrorism have surged since 2010 (see chart).

The past six months have seen a rash of far-right terrorist incidents. Last autumn a white nationalist killed 11 people at a synagogue in Pittsburgh. France broke up a plot to kill Emmanuel Macron, the president, and Spain arrested a fascist hoping to assassinate Pedro Sánchez, the prime minister. Germany uncovered an extremist cell in the army, allegedly planning to kill the foreign minister and others. In February America’s FBI arrested a Coast Guard officer who had an arsenal and a target-list of Democratic politicians.

Globally, white-nationalist terrorism is far less deadly than the jihadist variety. But it is more prevalent than authorities acknowledge, says Jacob Aasland Ravndal of Norway’s Centre for Research on Extremism. Legal definitions of terrorism often require that an attack be planned in advance. Much extreme-right violence is spontaneous. Even burning down a refugee centre may count as a hate crime, not terrorism. Europol, the EU ’s law-enforcement agency, ascribed just 3% of terrorist attacks in 2017 to the far right. But Mr Ravndal’s database of ideologically motivated violent incidents shows that in western Europe, though jihadists kill more people, the far right carry out more attacks.

More right than they know

If the threat from white nationalists is underestimated, that is partly because they are more publicity-shy. Mr Tarrant and his hero, Anders Breivik, who murdered 77 people in Norway in 2011, were exceptions. They left manifestos and tried to maximise media exposure. Indeed, the Christchurch killer also resembled sophisticated jihadist outfits, both in the ostentatious cruelty of his crime and in his hope that it would polarise society, fuelling yet more extremism.

The Breivik tradition Islamic State tries to provoke the West into persecuting Muslims and thus driving sympathisers from the “grey zone” towards radical participation. Right-wing extremists may also hope to provoke an Islamist backlash. Police are investigating a possible terrorist motive behind the murder of three people on a tram in Utrecht in the Netherlands, three days after the massacre in Christchurch. A Turkish-born suspect has been arrested. In Turkey President Recep Tayyip Erdogan has seized on the attack in Christchurch as evidence of a broad conspiracy against Turkey and Islam. He has quoted from the killer’s manifesto, which includes calls to expel Turks from Europe and to kill Mr Erdogan. The president’s not-so-subtle message is that only he can protect Turks from rampant white nationalism. The Christchurch killer also hoped to provoke stricter gun laws, so that gun-owners would rise up in revolt. There is not much chance of more gun control in America, Mr Tarrant’s primary target. However, Jacinda Ardern, New Zealand’s prime minister, is moving to tighten her country’s lax gun laws. This will not start a civil war. New Zealand prides itself on multiculturalism (see article). Its politics are more moderate than Australia’s. That, along with its easy gun laws, may have been why Mr Tarrant picked New Zealand. He wrote that he wanted to prove that nowhere was safe. Muslims in Christchurch have lost all sense of security. Tofazzal Alam, who survived the attack, says he is now afraid “to go to mosque, afraid of any crowd, afraid even to open the door”.

Yet the killer’s manifesto was inspired by events far away in Europe. He claimed he was converted to radical-right ideology on a trip to France in 2017, when he saw how much of the population was Muslim. He decorated his flak jacket with a “black sun”, a symbol traced to a floor motif used in his castle by Heinrich Himmler, a Nazi leader. He decorated his weapons with the names of victims of jihadist attacks in Stockholm and Paris. Before the shootings, he listened in his car to “God is a Serb”, a song written in 1993 in support of Radovan Karadzic—a Bosnian Serb leader convicted of genocide for his role in the massacre of 8,000 Muslims at Srebrenica in 1995.

The idea that Muslims and non-whites are “invaders” imported by a cosmopolitan elite to replace ethnic Europeans has its roots in thinkers of the French “new right” of the 1970s, such as Alain de Benoist and Renaud Camus. It is often linked to the belief that multicultural societies, far from promoting diversity, extinguish it by mixing distinct cultures and races together. The nuttiest apostles of such notions equate immigration with genocide.

These ideas attracted the anti-Muslim populist politicians who sprung up across Europe around the turn of the millennium, especially after the September 11th attacks in America. They inspired the far-right youth network Generation Identity. But the big impetus came in 2015-16, when some 2m asylum-seekers, mostly from the Middle East, poured into Europe.

For right-wing populists, this crisis was a godsend. Viktor Orban, Hungary’s prime minister, built a fence against the migrants and began calling himself a defender of Christian Europe. A frenzied opposition to Muslim immigration (real or imaginary) is the lodestar of populist-right parties in Germany, Poland, Sweden and Italy. At the European Parliament this month, Javier Ortega Smith of Vox, a new far-right Spanish party, thundered that had Spanish and Venetian fleets not won the battle of Lepanto against the Turks in 1571, every female MEP “would be wearing a burqa”.

Daniel Koehler of the German Institute on Radicalisation and De-radicalisation Studies says that it is no coincidence that extreme-right violence jumped during the migrant crisis, along with the fortunes of far-right parties: “If you think you have …to protect against ‘invaders’—how do you do that without using force?”

In America, too, the rise in extreme-right violence is linked to mainstream politics. Between 2009 and 2018, white supremacists killed more than three-quarters of the 313 people murdered by extremists. In 2016, the year Donald Trump won the presidency, more anti-Muslim assaults were reported to the FBI (127) than in any year since 2001 (93).

Such attacks rose steeply after Barack Obama’s election in 2008. Daryl Johnson, who spent 15 years studying right-wing terrorist groups, including at the Department of Homeland Security ( DHS ), wrote a paper in 2009 warning that the arrival that year of a black person in the White House could spark far-right violence. Demonised by conservatives for this, he left the DHS in 2010. Today, he says, it has no experts in right-wing terrorism. A spokesman did not deny this, but, in an email, said that the DHS is “committed to combating all forms of violent extremism, especially those that espouse racial supremacy or bigotry”.

In denial

Mr Trump has played down the threat of right-wing extremists, calling them “a small group of people that have very, very serious problems”. In 2017 his administration cancelled grants to groups combating white-supremacism. Peter Singer, a cyber-security expert at the New America Foundation who was invited to speak to Mr Trump’s national-security staff that year, said that they dismissed white-supremacist terrorism as “a law-enforcement issue”, and denied that it is transnational.

In fact, the ties between American and European extreme-right groups are ever closer. Europe’s Generation Identity groups are linked to Identity Evropa, one of the the American far-right organisations that planned a “Unite the Right” rally in Charlottesville, Virginia in 2017, where a white nationalist drove his car into a crowd and killed a counter-protester. Marchers at that rally chanted “Jews will not replace us”, referring to the same “great replacement” thesis shared by European extremists and the Christchurch killer.

Mr Trump has played the role for American white nationalists that such leaders as Mr Orban played for Europe’s, says Brian Levin, who heads the Centre for the Study of Hate and Extremism at California State University, San Bernardino. These groups, he says, saw their ideas, such as building a wall like Mr Orban’s, and banning or deporting Muslims, “getting into the mainstream tent”. They took this as a “green light” for violence. And he notes that, like the young on Europe’s extremist right, they have softened their image in the past decade. Shaved heads and combat boots have given way to army haircuts, polo shirts and corduroy jackets.

Far-right groups lack the state sponsors and safe havens enjoyed by some jihadists. Many on the extreme right admire Russia but it does not fit the bill. It has cultivated ties with far-right parties in Europe, but has snuffed out extremists at home. In the 2000s hate-motivated attacks, often directed at immigrants and internal migrants from the north Caucasus, reached nearly 700 a year, as the state flirted with nationalist movements. Clashes in Moscow in 2011 between police and far-right groups mixed with football hooligans showed the dangers of tolerating the ultranationalists. After they joined anti-government protests in 2011-12, the state began shutting them down, detaining the most violent. In 2014 war with Ukraine split the movement into pro-government and pro-Ukrainian factions. The SOVA Centre, an independent monitor, recorded just 57 hate-motivated attacks in 2018.

The Ukrainian model

Other Western white nationalists look to Ukraine itself, a hotbed of far-right activity since the Maidan uprising in 2014. Quasi-fascist militias, such as the Azov Battalion, have fought Russia in the east and taken a role in policing. So Kiev is “a place of attraction for the global far-right”, says Anton Shekhovtsov, of the University of Vienna. Some European radicals have joined Ukrainians on the front lines. American white supremacists have been spotted in Kiev. But as Mr Shekhovtsov puts it, “migration is a first-world problem”, and, whereas earlier far-right groups would beat up foreigners from Africa and Asia, Azov is keener on disrupting gay-pride marches. In any case, Ukrainian men seeking romantic violence have plenty to do in the east.

A more pressing concern for Western governments is far-right radicalism within their armed forces. Soldiers, obviously, are trained and have access to weapons. In America the DHS warned a decade ago that right-wing extremists will attempt to “recruit and radicalise” veterans, recalling the terrorist attacks of the 1990s by bitter ex-soldiers, such as the Oklahoma City bombing. A study of 119 lone-actor terrorists across America and Europe since 1990 found that 26% had done military service.

Racial tension is rising in the armed services. A recent poll by Military Times, a newspaper, found that over half of non-white American service members had suffered racism in 2018, up from 42% in the previous year. In 2017 two marines were arrested for hanging a white-supremacist banner on a building in North Carolina. On March 18th the Huffington Post, a news website, identified seven serving American soldiers as active in Identity Evropa.

The German authorities are investigating some 450 cases of suspected right-wing extremism in the Bundeswehr. Last year the security services identified dozens of police and soldiers as members of Reichsbürger, a far-right movement. In Britain in September 2017 four soldiers were arrested for membership of National Action, a banned neo-Nazi group. “If we get enough of us into the Army,” suggested one, “we’ll be in the right place when things start to collapse.”

Armies are tightening their vetting procedures and becoming more vigilant. They insist that adherence to law is drilled into recruits. But, for good reason, most armed forces are prohibited from conducting political education.

Tracking sources of danger is hard because, as Mr Koehler, the German scholar, points out, far-right violence typically involves loose groups of individuals radicalised on social media. He calls this “hive terrorism”. It is practically impossible to predict when someone will go from wishing others dead to actually killing them.

The Christchurch killer is a perfect example. He spent time on 8chan, a messageboard that prides itself on allowing users to post anything not illegal under American law. (After the attack, its administrators said they would co-operate with police.) It concerns itself with everything from Japanese cartoons to role-playing games. Anonymous posting is the norm.

The board’s “Politically Incorrect” subsections are far-right haunts. Their culture is a self-consciously puerile mishmash of memes, absurdism and irony, making it hard to know how seriously to take anything posted there. When Mr Tarrant declared on 8chan that he was about to commit murder, and proceeded to live-stream it on Facebook, many replies expressed surprise (often pleased) that the promised shooting spree was actually happening.

The killer’s manifesto, too, is steeped in 8chan-like irony, a style sometimes termed “shitposting”. Serious rants about low European birth-rates alternate with claims to have been radicalised by “Spyro the Dragon 3”, a children’s video game. If the media took such claims seriously, they would prove their own cluelessness.

Since the attacks, there have been calls for internet platforms to do a better job of restricting violent right-wing content. Facebook has been blamed for letting the live-stream of the attack go on for 17 minutes. The platform says it began vigorously blocking the video as soon as it discovered it, removing 1.5m attempts to repost it. But internet users could still find copies hours after the attack. (It did not help that some “mainstream” media sites—and even Mr Erdogan—used some of it.)

Big internet platforms could do more, but they face a gargantuan task. The underlying problem, says Ben Nimmo of the Oxford Internet Institute, is that “radicalising content is not constant”—one viewer’s trigger to violence is another’s harmless satire. Hopes that artificial intelligence might do much of the filtering have not worked out; armies of human reviewers are still needed, and even they often err.

However hard it is to stop terrorists exploiting the internet, other citizens can, at least, refuse to help them. The Christchurch killer’s fixation on the former Yugoslavia is apt: as in that war, white nationalists seek to use spectacular violence and propaganda to turn citizens against each other. In New Zealand Ms Ardern has turned this on its head. She has tried to use horrific slaughter to unite a country in opposition to a creed whose most famous new exponent she refuses to name.