The share of minors among suspects and defendants in terrorism-related crimes in European countries, particularly in the EU, has grown significantly in recent years. The radicalization of young people under the influence of extremist ideologies is a worrying trend that requires a comprehensive response, writes The Wall Street Journal (WSJ), citing experts.

According to the Royal College of London, about a third of those accused and suspected of terrorism in Belgium in 2022-2024 were teenagers, while in the UK it is one in five of those arrested. Since 2025, dozens of teenagers aged 14 and older have been arrested across Europe in connection with attacks on music venues, shopping centers, and places of worship of various faiths, the WSJ notes.

Experts cited the unprecedented spread of extremist ideology on social media, which is being refined due to artificial intelligence technologies, the significant influence of social media on teenagers, and high-profile and divisive events such as the war in Gaza as the main factors contributing to the radicalization of young people. As pointed out by Peter Newman, professor of security at the Royal College, about two-thirds of all those detained in European countries on terrorism-related charges in the first eight months after the October 7, 2023 attacks on Israel were minors. At the same time, the total number of successful terrorist attacks in Europe doubled between 2023 and 2024, reaching 67.

Islamic extremist doctrines pose the main threat in terms of their influence on teenagers in Europe, but at the same time, there is a growing popularity of radical far-right ideas among minors. At the same time, extremist ideas on the internet tend to mix—white supremacists may admire the principles of Islamic terrorists, while young jihadists borrow the language and aesthetics of the European right. The Australian Institute for Economics and Peace points out that the radicalization of young people has accelerated significantly due to the internet — according to estimates, in 2002 it took 16 months to develop extremist views, whereas in 2015 this process accelerated by 40%.

Experts note that teenagers facing social problems among their peers are the first to become involved in online communities based on extremist ideas, conspiracy theories, and calls for violence. Experts believe that states should demand better content moderation from large social media  and greater efforts to combat the spread of extremist ideas.