The recent terrorist attacks in Europe are presumably not just acts committed by individuals, but acts facilitated by larger jihadist networks. But how do such networks operate? Understanding their modus operandi can be useful knowledge to counter terrorist threats.

In 2012, the Dutch National Coordinator for Security and Counterterrorism and the Dutch Probation Service launched a reintegration project for offenders on probation or parole who were (suspected to be) involved in jihadist extremism or terrorism. The initiative's primary goal was to reduce the chance…

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

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

People who are arrested on suspicion of preparing an attack are at risk of becoming radicalised either during or after their detention. Whether or not to arrest someone requires careful consideration. At the end of the prison sentence, it is important to provide effective supervision of the reintegration…

This study focuses on increasing our understanding of the different pathways converts take during conversion to Islam.

Since 2012, thousands of individuals have traveled from Western countries to join jihadist groups in Syria and Iraq. While much has been written about these individuals, only sparse attention has been paid to the social environment of these jihadist travelers and, more specific, the role of family members…

How do European Muslim men and women become involved in a violent jihadist struggle abroad?

The group structure of Jihadist networks changes rapidly, which makes it difficult to monitor them. This is the finding of research by criminologist Jasper de Bie. PhD defence 14 April.

In this article, Bart Schuurman and Sarah Louise Carthy conduct further research into the understanding of the causes of terrorism by assessing differences and similarities between left-, right- and jihadist extremists and terrorists. The article draws on the Analysen zum Terrorismus, one of the most…

What does the daily life of those who travelled to Syria to join jihadist groups look like? Destination Syria, a new ISGA report, provides answers to this question

Peter Grol and Edwin Bakker, professor of Terrorism and Counterterrorism at the University, presented their book ‘Dutch Jihadists’ for a large audience. The book tells individual stories of jihadists in Holland and of Syria-goers and should contribute to a better insight into their backgrounds and m…

Terrorism experts Daan Weggemans (Leiden University) and Beatrice de Graaf (Utrecht University) conducted one of the first scientific studies on the societal reintegration of jihadist former detainees. They showed that the reintegration process isn't without problems. Their conlusions are presented…

How do authorities and citizens construct meaning in the aftermath of jihadist terrorist attacks through the use of frames, rituals, and symbols. What does this reveal about the communicative impact of terrorism?

The number of young Western women travelling abroad to join the

Edited by Michael Kowalski

COUNTERRR examines domestic responses to jihadist armed groups in Africa, analyzing variation in state repression, community resistance, and the evolution of security across Mali, Nigeria, and Mozambique.

COUNTERRR examines domestic responses to jihadist armed groups in Africa, analyzing variation in state repression, community resistance, and the evolution of security across Mali, Nigeria, and Mozambique.

How do the pathways of Dutch converts to Islam involved in jihadist movements differ from those of Dutch converts who are not, in terms of their life prior to Islam, their conversion experience and the form of involvement with the Islamic community after conversion?

In this article, Jeanine de Roy van Zuijdewijn and Edwin Bakker provide a big picture reflection on two decades after 9/11 in Western Europe.

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.

In the Master's programme Crisis and Security Management, specialisation Terrorism and Political Violence, we focus on the academic body of knowledge on different form of protests, contention, resistance and violence. We explore and explain the emergence of radical and extremist movement.

An exploratory study on the role of family members of those who joined jihadist groups

Terrorism experts Daan Weggemans (Leiden University) and Beatrice de Graaf (Utrecht University) conducted one of the first scientific studies on the societal reintegration of jihadist former detainees. They showed that the reintegration process isn't without problems. Their conlusions are presented…

The 2012 crisis in Mali, where the state collapsed and terrorist groups took over the north, came as a surprise to many. Mali had been considered a poster-child for democracy and was judged as considerably more stable than its neighbors by leading quantitative indices of state fragility. This article…

How to minimalize the chance of recidivism for extremist prisoners.

When does radicalization not lead to terrorist attacks?

This project aims at recording and safeguarding parts of the intangible cultural heritage of the Dogon in central Mali. A major song cycle, the baja ni, forms an integral part of Dogon funeral traditions. The song cycle is attributed to Abirè, a blind Dogon poet/prophet, probably from the 19th c., who…

The Terrorism and Political Violence research group at Leiden University examines the causes of radicalisation, the tactics of extremist groups, and the effectiveness of counter-terrorism policies. We also explore the role of the media and the influence of postcolonial legacies in the Global South,…

Most families were utterly overwhelmed when they found out that their son or daughter had suddenly left for Syria, that is what Daan Weggemans, Marieke van der Zwan and Marieke Liem observe in their research on family members of Dutch jihadists.

This article researches the public perception of terrorist attacks by measuring the importance the public assigns to attributes of terrorist attacks.

European countries struggling how to deal with the issue of returning foreign fighters, women and children from the Caliphate.

This research examines how right-wing extremist parents perceive and discuss their role in the ideological socialisation of their children.

Although Islamic State has largely been beaten, for now the Jihad scene in the Netherlands is more than alive. That is what professor Edwin Bakker (terrorism and counterterrorism) recently said in an interview in the Algemeen Dagblad.

From 2012 onwards the primary scholarly and media focus in regard to foreign fighters has been on the large number of Westerners joining jihadist groups in Syria and Iraq. Yet, much less attention has been paid to another conflict in the ring around Europe that attracted foreign fighters: the Russo-Ukrainian…

An international comparative study of the Netherlands, Belgium, Denmark, France, Germany, the United Kingdom and the United States.

This book underscores the interplay between religion and politics (local and global) in the production, escalation, management, mitigation, and resolution of conflict.

In the track Terrorism and Political Violence you will be familiarised with the academic debate regarding these contested concepts.

Bart Schuurman is a research Fellow at the International Centre for Counterterrorism (ICCT) and at the Institute of Security and Global Affairs (ISGA) in The Hague. He was interviewed by Abigail Esman of the Investigative Project on Terrorism (IPT) about his new book 'Becoming A European Homegrown Jihadist'.…

There is something strange about all the comments relating to the Jihadist-movies that flood across the social media.

Researchers from Leiden University have investigated the living conditions of Dutch fighters in Syria. Their report is central to a panel discussion on Tuesday, 24 May.

On the 25th of February, CTC researcher Daan Weggemans participated in a hearing of the permanent commission for social affairs and employment. During the hearing the issue of radicalization was discussed in two sessions. The first session gave members of parliament the opportunity to discuss the manifestations…

What insights do eleven social Facebook-accounts of Dutch and Belgic foreign fighters offer with respect to the phenomenon of so-called returnees?

The Dutch Department of Justice will give imprisoned terrorists the opportunity to earn money. This should have an positive effect on the resocialisation of detainees.

On 13 November 2025, the project team and experts on insurgency and counterinsurgency across Africa and beyond came together in The Hague to discuss current trends in research on government and community responses to jihadist insurgencies in Africa.

The Institute of Security and Global Affairs (ISGA) hosts two research journals and publishes the ISGA Reports series. Besides its own publications, researchers at ISGA also publish books or journal articles elsewhere. You can find all these external publications under Research output on the right.

In its magazine National Security and Crisis Management, the Ministry of Security and Justice paid extensive attention to the ISGA Conference ‘Who determines the security (research) agenda?’. Leiden researchers presented their research on important themes like the national security agenda, crisis management,…

Jasper de Bie, who obtained his doctoral degree at the Institute of Criminal Law & Criminology and who is currently employed by the Ministry of Security and Justice, has been awarded an honourable third place in the international competition 'TRI Award for the Best Doctoral Dissertation on Terrorism…