Five years on from Christchurch: Assessing the evolution of the threat landscape and policy response

15 March 2024

By: Milo Comerford, Jacob Davey, Jakob Guhl, Hannah Rose and Michel Seibriger

Content notice: This article contains references to terrorism, violence and extreme racism. 

In the five years since the Christchurch attack, the act of white supremacist terror has become the basis for a wave of copycats inspired by both its method and ideology. This article considers the significance of the attack and assesses the international policy response.

On 15 March 2019, a 28-year-old Australian terrorist killed 51 Muslim worshippers at Al Noor Mosque and the Linwood Islamic Centre in Christchurch, New Zealand, leaving a community and country traumatised. The attacker livestreamed the violence on social media, hoping to maximise the attention his actions and ideas would receive. He also published a 74-page manifesto, titled “The Great Replacement”, on 8chan outlining his worldview and calling on like-minded extremists to follow his example.  

In this article we examine the continued international impact of this attack five years later, including the influence on the aesthetic and methodology of accelerationist violence and the continued amplification of the ‘Great Replacement’ conspiracy myth at the heart of the attacker’s manifesto. We also look at the attack’s long-term effect on international policy responses to far-right extremism, including through the Christchurch Call initiative established in the attack’s aftermath. 

Mainstreaming of the ‘Great Replacement’ 

Following the Christchurch attack, there was considerable media coverage of the role of digital platforms in spreading the shooters’ livestream and manifesto. However, social media was also crucial in amplifying discussions of the Great Replacement to both extremist and mainstream audiences, something first evidenced by ISD in 2019.

In this analysis, we explore the current state of online discussion around the Great Replacement theory, identifying its continued resonance within both online fringes and the mainstream. We also demonstrate how major social media platforms are still core hubs for extremist actors to shape discussion. This analysis was conducted using the social listening tool Brandwatch to identify tweets made on X (formerly Twitter) containing keywords associated with the theory[i].

Prevalence of Great Replacement rhetoric

Our analysis demonstrates the importance of mainstream political discourse in driving discussion of the Great Replacement. Since the start of the year, we found an apparent correlation between real-life developments and spikes in mentions of the conspiracy theory and related concepts: for example, the Supreme Court ruling in January 2024 allowing US government agents to remove razor wire at the US-Mexican border led to a surge in mentions of an ‘invasion’.

Prominent public figures also play a part in the theory’s mainstreaming. A tweet from the Tucker Carlson Network quipping “Your Great Replacement”, directed at media outlets such as CNN, reached 1.5M views, the highest in the sample, on 3 January. Meanwhile, former Republican presidential candidate Vivek Ramaswamy’s claim that the Great Replacement was “not a theory” led to more than 12.8K mentions on 9 January 2024. 

Volume over time since 1 January 2024, Great Replacement keywords (above) and related concepts (below), encircled peaks include Tucker Carlson’s ad campaign, Vivek Ramaswamy’s comments on the Great Replacement theory, and reactions to the SCOTUS ruling.

Graph 1: Volume over time since 1 January 2024, Great Replacement keywords (above) and related concepts (below), encircled peaks include Tucker Carlson’s ad campaign, Vivek Ramaswamy’s comments on the Great Replacement theory, and reactions to the SCOTUS ruling.

This reflects several trends first documented in 2019, including the link between high-profile stories about migration and discussion of the conspiracy theory, and the role of elected officials and political candidates in its spread. It also demonstrates the ongoing influence of high-profile influencers such as Tucker Carlson, who sanitise extremist talking points for more mainstream audiences.

Mainstreaming dynamics: Key influencers

The trend of continued mainstreaming of the Great Replacement and related concepts is further corroborated when looking at the 10 most active accounts that mention the Great Replacement theory and related concepts on X. Since January 2024, eight of these accounts openly endorse the conspiracy theory, with only one explicitly opposing it.  Of the top accounts referencing related concepts, most amplify far-right conspiracy theories including mentions of an ‘alien invasion’ facilitated by the US government, white genocide and antisemitic tropes. These accounts include French writer Renaud Camus, who originally coined the Great Replacement in an eponymous book in 2011. 

These trends likely reflect shifts in the enforcement of Terms of Service under Elon Musk. Nevertheless, the continued presence of extremist actors on X, their ability to dominate online discourse on these tropes and their key role in amplifying harmful myths five years after the Christchurch attack emphasise how digital platforms can be permissive environments for extremist narratives.

Continued Influence on Contemporary Violent Extremism 

The past five years have also seen the Christchurch attacker’s modus operandi, aesthetics and propaganda become seminal influences for international accelerationist attacks. Those copycat attackers glorified the terrorist as a ‘saint’ and made similar use of livestreams, manifestos and ideological messages about guns.

Inspiring copycat attackers

Every year since the Christchurch attack, there have been copycat accelerationist attacks. In 2019, the same year as Christchurch, there was also an attack on a synagogue in Poway, California; a supermarket in El Paso, Texas; a mosque in Baerum, Norway; and a synagogue in Halle, Germany. In 2021, following the pandemic, there was an attack on a school in Eslöv, Sweden. In 2022, a supermarket in Buffalo, New York; an LGBTQ+ bar in Bratislava, Slovakia; and a LGBTQ+ bar in Colorado Springs, Colorado, were targeted. In 2023, it was a dollar store in Jacksonville, Florida.

It also inspired a plot to attack two mosques in Singapore on the second anniversary of the attack (2021). In each case, perpetrators referenced predecessors in the violent accelerationist movement, with Christchurch cited as the key ideological and operational influence.

While recognising the bias of propaganda, attack manifestos open a vital window to terrorists’ self-perception of motivation. The 2019 Poway shooter’s manifesto identified the Christchurch attacker as a personal “catalyst” who inspired his actions; the 2021 Buffalo shooter wrote in his manifesto that “without his livestream I would likely have no idea about the real problems the West is facing.” Finally, in a nod to Christchurch’s long-term legacy, the 2022 Bratislava shooter labelled the attacker in his pre-attack manifesto as “a symbol of our struggle,” adding that his “words continue to ring true even years later.”

Saints Culture

The Christchurch attacker has also been hagiographed, or glorified as a saint, in communities such as chan image boards and white supremacist ‘Terrorgram’ channels on Telegram into a pre-existing ‘Saints culture‘. By turning terrorists into ‘iconic figures of worship’ and painting their actions as devotion to their cause, Saints culture has successfully motivated copycat attacks from violent accelerationists. 

These online subcultures feature specific aesthetics and dark humour which aim to lower barriers to violence and reduce terrorism to a real-life game which can be played and ‘won’. ISD research from 2021 showed how the Christchurch anniversary of 15 March elicits a particular rise in expressions of support for the attacker, conspiratorial claims that Christchurch was a ‘false flag’ and miscellaneous ‘shitposting’ related to the attack on imageboards such as 4chan.

Figure 1: A meme depicting the canonisation of the Christchurch attacker by Adolf Hitler and a terrorist who killed nine African Americans at a church in Charleston, South Carolina.

Figure 1: A meme depicting the canonisation of the Christchurch attacker by Adolf Hitler and a terrorist who killed nine African Americans at a church in Charleston, South Carolina.


Even before Christchurch, calls for individuals to carry out extreme-right terrorist attacks were slowly gaining traction through older texts including Leaderless Resistance, The Turner Diaries and Siege. But the Christchurch attacker’s first-person shooter style livestream was especially significant in motivating offline action. While previous attackers had published or written manifestos (e.g. the 2011 Oslo attacker) or filmed their attacks (the al-Qaeda inspired 2012 attack on a Jewish school in Tolouse), the Christchurch terrorist was the first to livestream an on-going attack. Throughout the Buffalo shooter’s manifesto and Discord diaries, he credits the Christchurch attacker with his own radicalisation to violence. In a post on 9 December 2021, the Buffalo shooter wrote that “if [he] didn’t livestream his actions that day, then I don’t think I would be writing this as I do currently.”

Ideological messages on guns

The writing on the attacker’s guns, which contained extremist phrases, symbols and tags, added further ideological signalling. Future attackers, including the Buffalo and Bratislava shooters, adopted this approach adding swastikas, in reference to previous attacks and hateful slurs. These writings speak to their inspiration but also call out to fellow violent extremists through in-group references and visualisations of their ideological programme. Despite not necessarily bearing an ideological link, similar aesthetics may also have been referenced in a recent shooting this year at a Houston megachurch. 

Figure 2: Guns used in attacks in Buffalo (left) and Jacksonville (right).

Figure 2: Guns used in attacks in Buffalo (left) and Jacksonville (right).

From the Christchurch attacker’s deep roots in extremist online networks to the aesthetics of his attack to his desire to motivate future terrorism, five years later he remains central to the development of accelerationist ideology, aesthetics and mobilisation to violence. It is difficult to overstate his seminal and continued influence on this extremist ecosystem.

Assessing the International Policy Response 

The day of the Christchurch attack provided an unfortunately overdue wakeup call to both platforms and governments around the online far-right threat. The Royal Commission of Inquiry on the attack painted a clear picture of a terrorist embedded in an unregulated online extremist ecosystem, inspired and instructed by YouTube videos, Facebook groups and extreme-right discussion boards such as 4chan and 8chan.

In the aftermath of the attack, New Zealand Prime Minister Jacinda Ardern and French President Emmanuel Macron established the Christchurch Call, an international plan of action and forum for heads of government, tech companies and civil society leaders aimed at curbing terrorist and violent extremist use of the internet.

The Christchurch Call: Putting the far-right on the agenda

Almost a decade after the 2011 Norway terrorist weaponised social media to globalise his attacks, the Christchurch Call succeeded in putting the digital far-right extremism threat on the international agenda. This was significant given that policy discussions on terrorism and violent extremist content previously focused primarily on the online activities of the Islamic State (IS). But five years on from Christchurch, what is the state of play of international policy responses to terrorism and violent extremism online?

At a high-level, the Christchurch Call remains an important vehicle for international coordination between policymakers, social media companies, civil society and researchers (ISD is a proud member of the Call’s Advisory Network). Its annual Leaders’ Summit provides crucial political momentum around this issue, including an opportunity to respond to emerging online trends. 

The 2023 summit focused on topics including generative AI and the impact of the 7 October attacks, which saw widespread proliferation of terrorist propaganda across mainstream platforms. However, concrete government and platform actions on the Call’s commitments are often obscure, with limited transparency mechanisms.

At an industry level, the Global Internet Forum to Counter Terrorism has developed new Content Incident Protocols for coordinating cross-platform responses to attacks like Christchurch. These Protocols, which have been activated six times, include ‘hash-sharing’ around livestreams and related perpetrator content (e.g. manifestos). 

However, although mainstream social media platforms continue to update their policies and enforcement against far-right extremism threats, the rolling back of data access to researchers makes it harder to judge if they are effectively tackling online extremist content, including the continued proliferation of Christchurch attack material. Finally, global coordination is stymied by the lack of consensus on the language and conceptualisations of far-right threats, despite several Five Eyes governments proscribing a handful of extreme-right groups (including Atomwaffen, Proud Boys and the Base).

Digital policy developments

More broadly, governments have built on existing ‘notice and takedown’ approaches to illegal content in recent years with a new wave of regulation aimed at improving platform transparency around the mitigations of systemic risks. Legislation such as the EU’s Digital Services Act, and the UK and Australia’s respective Online Safety Acts include specific provisions around the proliferation of violent extremist and terrorist content.

However, smaller ‘alt-tech’ platforms have not been the primary focus of regulation, despite their outsized influence within online extremist ecosystems. Recent ISD research found that extremist and hate actors linked to alt-tech platforms including Bitchute, Odysee, Gettr and Rumble more often than Facebook, Instagram or Reddit. With new research suggesting the Christchurch attacker was even more active in alternative online extremist spaces than originally thought, and with regulation on mainstream platforms likely to drive further migration, it remains essential for policy responses to consider the risks posed by this ‘long tail’ of smaller platforms. 


Five years on, the tragedy in Christchurch still creates ripples. The ideology which underpins it reaches global audiences, driven by permissive social platforms and aided by mainstream figures who implicitly or explicitly endorse the Great Replacement myth. 

The attack has had a concrete influence on the methodology of subsequent terrorists and the culture they have built around them. However, it also significantly impacted on solutions to this mounting threat. The Christchurch Call helped put the cultures which inspired this attack on the policy agenda, driving forward solutions to the spread of extremist content. Meanwhile evolutions in digital policy mean that the platforms which allow hate and violence to grow unchecked will increasingly be held to account. 

With the victims, survivors and families of the attack at the forefront of our minds on this anniversary, above all we are reminded of the terrible consequences of society’s collective failure, and the urgency of efforts to safeguard communities from its continued influence.  


  1. Two queries were made for this analysis using the social listening tool Brandwatch:
    1. Great replacement theory:  (“Great Replacement” OR “take our place” OR “will be a minority” OR “become a minority” OR “minority white” OR “will replace us”) OR
      ((migration OR migrant OR migrants OR immigration OR immigrant OR immigrants OR asylum) AND (replacement OR replace OR genocide OR “birth rate” OR “birth rates” OR ethnocide))
    2. Related concepts: “White genocide” OR remigration OR “birth rates” OR “we will become extinct” OR “white replacement” OR remigr* OR “replacement migration”
      OR “white minority”
       OR ((invasion OR ethnocide) NEAR/4 (alien OR migrants OR immigrants OR “asylum seekers” OR foreigners))