The terrorist attack in Christchurch which killed at least 50 Muslims, was not an isolated event.
Across Western countries, anti-Muslim hate crimes and violent attacks have been on the rise.
Earlier this year, the Anti-Defamation League reported that 2018 was the worst year for far-right killings in the United States since 1995, when Timothy McVeigh killed 168 people in Oklahoma City.
In Britain, the Government considers far-right extremism to be an increasing threat and recently for the first time proscribed a right-wing extremist group as "terrorist."
Germany's domestic intelligence service has observed a steady rise in the number of "potentially violent right-wing extremists," with current estimates at 13,000.
As with other forms of radicalisation, terrorism occurs when several factors converge: politics, ideology and the structures through which people are mobilised.
As far as politics is concerned, the process of polarisation in most Western countries has created widespread fears and insecurities. This narrative of fear has revolved around the effects of migration, especially from Muslim-majority countries, which populist politicians have presented as an existential threat to Western identity and "our way of life".
The rhetoric around the rise of Isis (Islamic State) and its terrorist campaigns in cities such as Paris, Brussels and London have not just confirmed these fears but given them a sense of greater urgency and immediacy, fuelling violent responses.
Like virtually all terrorists, the attacker in Christchurch described his action in defensive terms — both as a reaction to ongoing Muslim immigration and as retaliation for Islamist militant attacks. From his perspective, the corruption of Western political systems and the looming Muslim 'threat' made nonviolent activism pointless.
2) A supporting ideology
The second factor is an ideology that can turn such fears and grievances into a (more or less) coherent political project.
On the far-right, recent years have seen a profound shift away from the traditional focus on race towards supposedly more inclusive ideas such as identity and culture.
The "identitarian" movement emerged in France but has strongly influenced the US alt-right. It no longer speaks about colour of skin but expresses its agenda in cultural and civilisational terms — as a duty to preserve a so-called European identity against an aggressive assault by "non-European" cultures, in particular Islam.
According to identitarians, the enemy within is culturally Marxist elites who have systematically pursued the replacement of white European populations through mass migration.
The power of the identitarian ideology lies in the fact that it is not openly racist but easily accommodates those who are.
By talking about culture and identity instead of race, it describes groups that are not white and/or Christian as undesirable without referencing their ethnicity or skin colour, enabling the far-right movement to connect with broader sections of the populist right.
At the same time, individual racists such as former Ku Klux Klan leader David Duke understand perfectly well that identitarian concepts are compatible — if not synonymous — with their own, more old-fashioned ideology. Instead of white supremacism, for example, identitarians talk about ethno-pluralism — which sounds neutral, even progressive, but essentially means the same thing.
4) Connections to the past
On a personal level, the identitarian ideology makes it possible for terrorists to connect with a long line of warriors for "European culture."
As Thomas Hegghammer pointed out years ago, one of the strongest narratives for both Islamist militants and right-wing extremists is that of the Crusades. The Knights Templar was a Crusader order with a fearsome reputation in battles against Muslim adversaries.
Finally, terrorism usually requires structures through which people are mobilised into action.
In the case of the Christchurch attacker, this seems to have been the far-right's vast virtual subculture on platforms such as 8Chan, 4Chan, Reddit, Twitter and others.
While much of the attention in recent years has focused on the activity of Islamist militant groups on mainstream websites like Facebook, the far right's longer-standing — and, arguably, more extensive — presence in smaller discussion forums and blogs has gone almost unnoticed.
Yet, as George Hawley has shown, the rise of the alt-right and other far-right movements would be virtually inconceivable without the "Internet troll culture" from which they have emerged.
Beyond the ability to connect to like-minded people, being immersed in the far-right's online subculture gave the Christchurch suspect a sense of being part of a sizable and significant movement, with supporters everywhere in the world.
Like Norwegian extremist Anders Breivik, he did not see himself as a "lone attacker" but as a pioneer whose example many would follow.
The Christchurch attack should have come as no surprise.
The far-right is stronger and bolder today than ever.
Policymakers in all Western countries need to take it seriously because its violence not only threatens lives, but also undermines the very pluralism and freedom on which Western societies are based.
The first step is to admit that there is a problem. After all, we will never be able to deal with this threat unless we name it.
- Peter Neumann is a professor of security studies at King's College London and founding director of the International Centre for the Study of Radicalisation.