Shortly before he killed 51 people, the gunman who perpetrated the Christchurch, New Zealand, mosque shooting posted a manifesto to the website 8chan in which he praised a fellow white supremacist — the attacker who killed 77 people in Norway in 2011. A few weeks later, the Christchurch shooter was praised by another gunman — the one who perpetrated the synagogue shooting in Poway, California. Four months after that, yet another gunman, in the El Paso shooting, posted a similar white supremacist manifesto to 8chan. The attacks happened across the globe — in Europe, Oceania and America. But they followed similar playbooks and shared the same noxious ideas. In particular, the shooters in Christchurch, Poway and El Paso all cited the so-called Great Replacement theory — that Western countries and their white populations are under attack from a mass immigration of nonwhite immigrants orchestrated by Jews. The Great Replacement term was itself coined by Renaud Camus, a French writer. The connectivity between those massacres and their ideology is just one example of how white supremacists are forming alliances, working together and inspiring each other across borders. While white supremacists will sometimes call themselves “white nationalists,” experts say it’s more accurate to view them as members of an international movement that aims to advance a shared agenda. “They view themselves as part of a white collective that is transnational and that represents a race, the white race,” said Heidi Beirich, who founded the Global Project Against Hate and Extremism following a 20-year career at the Southern Poverty Law Center. “One of the big things motivating violence today … is this wish to bring whites together across borders to fight for control of what they consider their historic homelands.” One strong link between white supremacists in the United States and Europe, said Marilyn Mayo, a senior researcher at the Anti-Defamation League’s Center on Extremism, is hatred of Jews for their purported control of banks and the media — as well as their perceived support of immigration. (…) Some of the interaction between American and European extremists has involved members of far-right European political parties. The ADL’s Mayo says these politicians, and their increasing popularity in Europe, has inspired their American allies. American white supremacists in particular admire Russian President Vladimir Putin and Hungarian Prime Minister Viktor Orban, who has opposed immigration and also been accused of anti-Semitism. “They believe that people like Putin and Orban are promoting white Christian society where they’re keeping out influences like Third World immigrants,” Mayo said. “Putin is seen as the saving grace of white Christian culture. There isn’t as much immigration in Eastern Europe and white supremacists see it as a place to mirror.” Militant groups are linking up as well. Atomwaffen Division, a white supremacist group, has spawned offshoots in the United Kingdom, Germany and elsewhere. And white supremacists have traveled to Ukraine to link up with, train and in some cases reportedly fight with the Azov Battalion, a Ukrainian paramilitary unit with ultranationalist elements. In 2017, members of the Rise Above Movement, a white supremacist group in California, met with leaders from the Azov Battalion in Ukraine. Now, according to the Soufan Center report, Ukraine is serving the same function for white supremacists as Middle Eastern conflict zones have served for Islamic terror groups. In both cases, extremist groups take advantage of the lawlessness and combat opportunities of a war zone to recruit, radicalize and train adherents from around the globe. Excluding people from Russia, more than 2,000 foreigners have traveled to fight in Ukraine, though experts don’t know how many are joining extremist groups. That number includes dozens of people from the United States. “Ukraine [is] emerging as a hub in the broader network of transnational white supremacy extremism, attracting foreign recruits from all over the world,” the report says. “Where jihadis travel to fight in places like Syria, white supremacists now have their own theater in which to learn combat.” In order to combat these trends, experts say, tech giants need to take more aggressive action to remove extremists from their platforms. And they say the U.S. government must begin treating white supremacists like it treats ISIS and al-Qaida. That means sharing intelligence with other countries, tracking their finances and surveilling their communications. “If you look at what happened in [the Pittsburgh synagogue shooting], his tagline on Gab was ‘Jews are the children of Satan’ and he owned like 20-something guns,” Clarke said. “And if that guy was brown and his name was Mohammed and he said the word ‘jihad’ once and he owned as much as a slingshot, he probably would have been arrested.”