The research group on terrorism and political violence studies the phenomena of terrorism-related and other politically motivated violence.

Perspectives on Terrorism (PT), the peer-reviewed online journal of the Terrorism Research Initiative (TRI) and the Institute of Security and Global Affairs (ISGA), is published six times per year by the Editorial Team with the help of members of the Editorial Board and the journal’s…

Recently, Europe was again shaken by some attacks. This ‘Elementair Deeltje’ places terrorism in a historical perspective and gives an up-to-date overview of this form of political violence.

During the 1980s and early 2000s, authors like Alex Schmid and Andrew Silke demonstrated the paucity of first-hand insights being used to study terrorism and the consequences this had for the reliability of the findings beings presented. But to what extent have these issues endured?

This project aims to improve understanding of, and responses to, the phenomenon of lone actors through analysis of comprehensive data on cases from across Europe.

As terrorism scholars, we are intrigued by those who engage in violence. We study their motivations, tactics, ideology, organisational structures, and pathways to (de-)mobilisation, hoping to better understand terrorism and how we can counter it. Far less attention is paid to what happens after an attack…

Terrorism only poses a small risk to people but tends to be a major source of public fear. Through fear, terrorism has far-reaching implications for public governance.

It is in the interest of all democracies for young people to learn the value of free debate, even on sensitive and potentially divisive issues like terrorism, argue Thorbjørn Jagland (secretary general of the Council of Europe), Sayeeda Warsi (UK parliamentarian), and Francesco Ragazzi (Institute of…

One of the defining issues of our age, terrorism frequently makes headlines as governments, private businesses, and ordinary citizens find themselves at risk or under attack. But what is the nature of this threat, and what can be done about it?

This book contextualizes the use of terror as part of wider movements of political contention, demonstrating that terroristic innovation occurs as part of wider historical processes rather than in a vacuum.

In the track Governance of radicalism, extremism and terrorism you will be familiarised with the academic debate regarding these contested concepts.

A cautious response to a crisis or terrorist act avoids the creation of a culture of fear. This is another way to reduce our vulnerability to terrorism.

This article written by Marieke Liem & Alexander Kamprad investigates the relationship between terrorism and interpersonal violence. They conducted cross-national analyses on the effects of terrorism mortality rates on homicide rates. Results showed that terrorism appears to be robustly and positively…

Terrorist attacks are not an end in themselves, but a means of creating unrest and fear. Terrorism policies and research should focus more on managing fear and social unrest.

Few events have influenced our global order as intensely as the events of September 11, 2001.

With 16 research institutions and more than 120 individual scholars from more than 30 countries in its ranks, the Terrorism Research Initiative (TRI) constitutes one of the largest research consortia in the field of Terrorism Studies.

This research paper was requested by the European Parliament's Committee on Civil Liberties, Justice and Home Affairs. It was published by the International Centre for Counter-Terrorism (ICCT) in The Hague. Leiden University is one of the participating institutes in this publication and our researcher…

In December 2014, Leiden University’s Institute of Security and Global Affairs with the Australian National University’s Asia-Pacific College of Diplomacy and the International Centre for Counter-Terrorism, commenced a research project to assess how (temporary) military interventions can best prepare…

This paper investigates possible convergence of issue salience of terrorism among citizens within the European Union for ten jihadist attacks in the period 2015–2017 using Eurobarometer survey data.

Self-censorship violates principles of a free society but few people want to take the role of the martyr.

In recent years, the use of primary data in terrorism research has increased. In order to maximise the benefits of this trend, we want to encourage terrorism scholars to implement open science practices more systematically. This article therefore presents different avenues towards open and reproducible…

How have British, Dutch, and German security services dealt with political violence and terrorism since the late 1960s; to what extent did they consider these new phenomena as a task and how have they developed activities in order to counter these security threats?

From the research Terrorist threat in the Netherlands, the risk perception and opportunities for risk communication (Leiden University) shows that the Dutch respond relatively sober to attacks in neighboring countries and the possible risks of a terrorist threat. Half of the respondents believe that…

These three repors are part of a research project that assesses how military interventions can best prepare the ground for an effective long-term counter-terrorism policy. Three different cases have been studied, and they have each provided the input for the policy relevant recommendations that are…

Preventing terrorism before it happens seems like an idea no one would disagree to. But is it possible? How do counter-radicalisation policies look like? And are there dangers of unintended consequences? Francesco Ragazzi, Assistant Professor at Leiden University’s Institute of Political Science, has…

This collection includes six short policy-focused contributions exploring how legislation and policy on counter cyber terrorism unfold at the national level in the United States, the United Kingdom, China, Russia, France, and at the regional level of the European Union.

Comparing terrorist attacks with falling off a step ladder is absurd, writes Jeanine de Roy van Zuijdewijn in NRC Handelsblad on 27 September 2017.

On 20-21 June, the Society for Terrorism Research (STR) held its annual conference in Oslo. The Center for Research on Extremism (C-REX) of the University of Oslo led by Professor dr. Tore Bjørgo hosted one of the main academic conferences in the field of terrorism studies. The central theme was the…

The book addresses the question “How and why do people become involved in European homegrown jihadism?

The ‘Community Resilience Fund’, a programme of the Canadian federal government, approved a research grant for Dr. Bart Schuurman of the Institute of Security and Global Affairs.

This report examines the questions "What is the risk perception of the Dutch population regarding terrorist threat?" And "what are the possibilities for the Dutch government to communicate about terrorist threats and about (counter-) terrorism policy?"

What is the impact of terrorism? Researchers Jeanine de Roy van Zuijdewijn and Jessica Sciarone looked at ten jihadi attacks and concluded that there are major differences between European countries.

On 15 March, the 28-year-old Australian right-wing extremist Brenton Tarrant committed a terrorist attack on two mosques in Christchurch in New Zealand. Jelle van Buuren, Bart Schuurman, Daan Weggemans and Tahir Abbas all working at the Institute of Security and Global Affairs (ISGA) have been approached…

Academic research on terrorism is getting better all the time. This is the conclusion of university lecturer Bart Schuurman after studying 3,442 articles. He published his study in Terrorism and Political Violence.

Facebook and Google are being pressured more and more to prevent terrorists from accessing and using their platform. Right now, they are developing software that uses artificial intelligence to remove unwanted content. Researchers from Leiden University explain for the NOS how this works, and whether…

The project examines the political conflict in the Red River Valley of Louisiana between the majority-black Republican Party and the overwhelmingly white Democratic Party by studying the composition and actions of each party.

Are terrorist suspects willing to reintegrate back into society? Can they reintegrate?

This article presents an in-depth evaluation of a specialized reintegration initiative within the Dutch Probation Service focused on individuals convicted or suspected of involvement in terrorism.

Can conspiracy constructions explain for hatred of the system? And if so, should conspiracy constructions be considered to be a risk in terms of national security?

Jeanine de Roy van Zuijdewijn teaches the masterclass terrorism 2018 together with Edwin Bakker. Read the interview here.

You can find more information on the Dutch webpage. Click on the “Nederlands” button above.

Could policies aimed at preventing radicalisation undermine the very trust and social cohesion they aim to strengthen?

The MOOC Terrorism and Counterterrorism: Comparing Theory & Practice by Prof. Edwin Bakker, co-developed by the Centre for Innovation, has now attracted over 100,000 participants. It is the first MOOC of Leiden University to reach this magic number.

You can find more information on the Dutch webpage. Click on the “Nederlands” button above.