Right-wing violence is usually considered a dangerous form of domestic terrorism, but the horrific attack on two mosques in New Zealand on Friday shows its growing international dimensions. Brenton Tarrant, an Australian man, reportedly traveled to New Zealand, where he allegedly killed 49 worshippers at two mosques, wounding dozens of others. In addition, Tarrant appears to have been inspired by a 2011 attack in Norway, praised current U.S. political figures, and drew on U.S.-based social media platforms to spread his message. (Tarrant may have also had several accomplices.)

Just as jihadis look to figures like al-Qaida in Iraq leader Abu Musab al-Zarqawi or the Paris attackers as they plan their own violence, white nationalists like Tarrant now look globally before they strike. Anders Breivik, who killed eight people in a car bombing in Oslo and then 69 more in a sustained shooting attack on a summer camp for youth members of Norway’s Labor Party, wrote a 1,500 page manifesto he posted online before carrying out his massacre. Terrorism analysts believe that Tarrant saw Breivik as a model, aping his anti-migrant and anti-Muslim rhetoric. Tarrant declared in his own manifesto, “I have read the writings of [Charleston, South Carolina, church shooter] Dylann Roof and many others, but only really took true inspiration from Knight Justiciar Breivik,” referring to Breivik by the Norwegian’s self-image as a heroic defender of Christian civilization. Tarrant also claimed he was avenging the killing, in Sweden, of an 11-year old girl, who was run down by an asylum-seeker from Uzbekistan who drove a truck through a crowd in 2017.

Breivik is more than an ideological model—he is also a model for action. His mix of attacks, a car bombing and a shooting spree, combined with posting a long “treatise” to justify his murder offers a template for other white nationalists to follow, just as Columbine offered a model for troubled youths to conduct school shootings.

Because of the increasingly international nature of right-wing violence, the response must be international as well.

Right-wingers, however, are not just looking to the past. Tarrant also expressed admiration for President Donald Trump “as a symbol of renewed white identity and common purpose” and made reference to Black Lives Matter and Democratic Party critic Candace Owens. The reference to Owens may have been ironic—the document if rife with trolling and online in-jokes—but suggests a deep familiarity with U.S. culture war flashpoints. One would think that an Australian targeting New Zealand would not focus on America-specific concerns or personalities, but the broader issues—opposition to immigrants, hatred of racial and religious minorities, and scorn for liberals—are sadly more universal and show up in different forms in much of the world.

The technologies used to spread the word are also global. Tarrant apparently warned before the attack that he would livestream his violence on Facebook. He then used a helmet camera to do this while posting links to his own manifesto on Twitter and the message board 8chan. Although the major internet companies have been working to take down his content, it is likely to survive on at least some platforms and, as its author intended, inspire others to act.

Because of the increasingly international nature of right-wing violence, the response must be international as well. Intelligence cooperation, honed to a fine edge in the struggle against the Islamic State and other jihadi groups, can also be used against right-wing organizations. This would involve sharing information on known activists, tracking their connections across borders, disrupting attempts to fundraise in other countries, and otherwise making sure that pressure on these networks is not confined to national borders.

Because right-wing organizations exploit social media, technology companies must be part of the solution. Some of this effort should involve taking down right-wing sites and blocking prominent users, just as internet companies already do for jihadi groups. Some companies are already starting to take such measures. But there is more to be done than takedowns. Jigsaw and its partners, for example, designed a program to “redirect” individuals seeking jihadi content online to content that tried to turn them away from violence and radical ideas. Similar content for right-wing extremism should be created and promoted by social media companies. Borderline content might be prevented from being monetized, have the comments functioned disabled, and otherwise be limited in how it might spread.

The United States also needs to revisit the legal basis for going after right-wing terrorism and draw on its international power to do so. At the very least, existing counterterrorism laws should be applied to right-wing groups when appropriate. For example, Mary McCord and Jason Blazakis point out that groups like the Atomwaffen Division have a presence in Germany as well as the United States and thus could be designated as a foreign terrorist organization–a move that would subject the group’s followers to devastating legal and financial consequences. More broadly, the United States should consider legislation to expand government powers to go after white nationalist and similar groups. The rules should be different than going after jihadis, but many of the principles still apply.

We know white nationalist and other forms of right-wing violence are here to stay. The true question is whether the United States and other governments will treat it with the seriousness it deserves and work together to counter this growing international scourge.