By Julie Carlier
On November 13, 2015, one of the deadliest terrorist attacks in Europe took place in Paris. At the Stade de France, three terrorists blew themselves up at the entrance gates after they were denied entry to a football match between France and Germany. Other terrorists stormed the Bataclan concert hall, shot at visitors for hours, and blew themselves up. Terrorists opened fire on people at various terraces. These attacks, spread across the city, claimed a total of 130 lives. November 13, 2025, marked exactly ten years since these attacks took place; a moment to look back and reflect on the changes since then.
Threat
In Europe, jihadist terrorism remains the deadliest form of terrorism, with 24 terrorist attacks in 2024 resulting in five deaths and eighteen injuries. The conflict in Gaza, the war in Ukraine, and the fall of the government in Syria have contributed to the growth of terrorism and extreme violence (Europol, 2025). Therefore, the threat level in the Netherlands has been raised to level 4: substantial, since December 2023. In the UK, the terrorism threat level is ‘substantial’ as well, which means that an attack is likely (Security Service MI5, n.d.). In Australia, the threat level is ‘probable’, which they explain as: “there is a greater thaan fifty per cent chance of an onshore attack or attack planning in the next twelve months” (Australian Government,n.d.). The threat level in Canada is ‘medium’ since 2014, which translates to “a violent act of terrorism could occur” (Government of Canada, n.d).
Forms of terrorism
Since the Paris attacks, we have seen differences in the ways terrorists are recruited and attacks are carried out. For example, the ‘lone wolf’ phenomenon has become more visible. A ‘lone wolf’ is an individual who acts independently, without being ordered to do so or potentially affiliated with an organization (Burton & Stewart, 2008). Europol’s research revealed that of the 24 jihadist terrorist attacks in Europe, twenty were carried out by ‘lone wolves’ (2025). These perpetrators were not directed by an organization but did carry it out in the name of jihad. The attacks were not claimed, with one exception. ‘Lone wolf’ terrorism is more difficult to combat than organized terrorism, as it is not clear why a person radicalizes, and it is difficult for security services to identify this person early on.
Another threat is online recruitment and influence. For example, Dutch news broadcaster NOS recently wrote about sadistic online chat groups where young people are influenced to harm themselves or others. According to the NOS, manuals on how to make bombs and commit murders were distributed in these chat groups as well (2025). In February 2025, Europol already issued a warning about this trend, explaining how these young people are mostly recruited through online gaming platforms (Europol Empact, 2025). In addition to these online chat groups, social media channels such as TikTok, Instagram, and YouTube are also used to spread right-wing extremist or jihadist propaganda and recruit followers (Stockhammer, 2025).
The third increased threat that security services are detecting is that of sovereigns. Sovereigns are people who do not abide by government laws and rules because they believe the government has no legitimate authority over them. They view the legislative, judicial, and executive branches, science, and the media as an ‘evil elite’ (NCTV, 2024). A small number of sovereigns are willing to confront the government with violence. They then organize online or physically and plan these attacks together. In 2025, a major trial took place in The Netherlands against the sovereign organization Common Law Netherlands Earth, where ten suspects were tried for, among other things, involvement in this criminal organization and incitement to commit a terrorist offense.
The so-called ‘sovereign citizen movement’ is not only active in The Netherlands, but also in the United States, Canada, New Zealand, United Kingdom and Australia (Program on Extremism, 2025). In 2025, a self-claimed sovereign citizen was accused of killing two police officers in Porepinkah, Victoria (Tsikas, 2025). In the United States there are sources that claim that sovereign citizens collaborate with hard-right-extremists and that some of these sovereign citizens use violence, mainly against police (Farley & Goldwasser, 2025).
What does this mean for event safety?
When we apply this knowledge to event preparation, two recommendations can be made. Firstly, the developments mentioned call for an adjustment to the (terrorist) threat. Lone wolves, self-radicalized individuals, and sovereigns are more difficult for intelligence services to track, and in the absence of contact with a central organization, there is a greater chance that an attacker will not be detected before carrying out an attack. Secondly, the likely types of attacks that need to be considered have become more diverse. Many security plans still include the scenario of a ‘bomb threat’ or ‘suspicious package,’ but that may no longer the likeliest form of terrorist threat. An event organizer can also consider taking knife attacks, driving a car into the crowd, or arson into account. Is there an increased threat due to, for example, social context, the nature of the event, its open character, or the VIPs or artists present? By making a broader threat assessment in the risk analysis, it can be examined more specifically whether such risks are reasonably foreseeable and what this means for security, evacuating safety, and incident response preparations. Discuss within your organization what this means for your planning, staff training, and collaboration with emergency services. Consider whether a risk assessment meeting, a simulation study or tabletop exercise would be beneficial for these types of scenarios.
The attacks on the Bataclan, Stade de France and terraces in Paris will be remembered forever, and even today it is felt throughout the country. The threat in 2025 has changed, but we continue to learn from the past and look ahead. It is important for event organizers and stakeholders to become more resilient to this changing threat.