Beyond the immediately visible plenum, parliaments are highly complex institutions. They work through various venues in which decisions are prepared or even taken. The two main institutions in this regard are parliamentary party groups, which comprise legislators who are elected under the same party…

This paper contributes on an increasing body of work on radicalisation. It specifically focuses on what distinguishes individuals whose behavioural radicalisation includes involvement in terrorist violence from those whose behavioural radicalisation does not.

This interdisciplinary study focuses on (trans)national ethnic and popular networks, combining historical-ethnographic and computational methods to understand the ‘workings’ of networked conflict interfering in the increasingly violent conflict in the Sahel (Africa) and beyond. The project focuses on…

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?

This book concentrates on the regulation of political parties in the EU post-communist democracies, and on Bulgaria, Croatia, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Slovakia, Slovenia and Romania, in particular.

In this paper, Kantorowicz argues that reverse party favoritism exists. He exploits the fact that during the SARS-CoV-2 pandemic crisis, the Polish government was keen to launch postal voting in the presidential elections scheduled for May 2020.

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.

The Dutch and English East India Companies were formidable organizations that were gifted with expansive powers that allowed them to conduct diplomacy, wage war and seize territorial possessions. But they did not move into an empty arena in which they were free to deploy these powers without resista…

Violence during war often involves upswings and downturns that have, to date, been insufficiently explained. Why does violence at a particular point in time increase in intensity and why do actors in war decrease the level of violence at other points? Duyvesteyn discusses the potential explanatory variables…

A new paperback edition of Brian Heffernan's book Freedom and the Fifth Commandment. Catholic priests and political violence in Ireland, 1919-21 was published by Manchester University Press in September 2016.

How many written parliamentary questions does each party put to each minister? Political scientists Simon Otjes (University of Groningen) and Tom Louwerse (Leiden University) studied the practice in Dutch parliament and found that parties use parliamentary questions strategically as part of their ‘permanent…

This book uses a biographical approach to explore the Labour Party's relationship with European integration, moving beyond simple 'pro' or 'anti' labels to showcase the complexity of views that have existed.

Policy Note Insecurity in Burkina Faso – beyond conflict minerals: The complex links between artisanal gold mining and violence

Slavoj Žižek is one of the most prominent public intellectuals of the left. His central claim holds that “today, it is more crucial than ever to continue to question the very foundations of capitalism as a global system”.

Cynthia van Vonno, political scientist at Leiden University, explains why individual MPs vote according to the party group line.

On Wednesday 14 May 2025 Remzi Çakırlar successfully defended a doctoral thesis and graduated.

China is a one-party regime, yet elections are held for the local congresses. PhD candidate Wang Zhongyuan investigated how the Communist Party uses this democratic instrument to strengthen the authoritarian regime. PhD defence 31 January.

Why, then, do governments choose to disclose intelligence and what factors shape how they do so?

Firearms and violence in Europe–A systematic review by Katharina Krüsselmann, Pauline Aarten, Marieke Liem

On 1 April 2020, Ivan Romashchenko defended his thesis 'Related Party Transactions and Corporate Groups: When Eastern Europe Meets the West'. The doctoral research was supervised by Prof. S.M. Bartman en Prof. A. Radwan (Kaunas, Lithuania).

How can we explain that Caribbean small states have the most stable two-party systems in the world, while Pacific small states have either very weak parties or no parties at all? Matthew Louis Bishop (University of Sheffield, UK), Jack Corbett (University of Southampton, UK) and Wouter Veenendaal (Leiden…

Behavioral Sciences Mental Health Psychological Disorders - Adult Aggression in Adults Psychological Science Social Psychology Criminology & Delinquency Social Sciences Criminology and Criminal Justice Crime and Crime Prevention Criminal Behaviour and Forensic Psychology Violent Crime Law Criminology…

Violence such as assault or head-butting causes pain, shock and distress. It is often seen as savage or senseless. But for those who commit it, violence has meaning, argues violence researcher Don Weenink in his inaugural lecture.

Refugees’ effect on domestic terrorism is conditioned by host-country social perception (attitude about living next-door to foreigners) and economic competition. These hypotheses are tested cross-nationally from 1995-2014 leveraging data from the World Values Survey.

This book presents an understanding of the concept of Countering Violent Extremism from a critical terrorism studies perspective using case studies from different countries while examining the issues it raises.

In this publication, May Tamimova and Tahir Abbas researched the existing literature about violence and hatred against places of worship.

The European Homicide Monitor (EHM) offers a standardized framework for countries and regions to compare homicide characteristics, patterns and trends.

This article provides a comprehensive analysis of the Islamic State's use of images taken by drones, drawing on a dataset of ISIS propaganda images from October 2016 to December 2018.

Terrorist groups adapt to environmental changes to maintain power. This project provides new insights by developing a theory of strategic target selection and using big data analytics and machine learning to test these hypotheses.

This paper presents the prevalence and characteristics of firearm homicides in Denmark, Finland, the Netherlands, Sweden and Switzerland

On Tuesday 23 May 2017, Jasmina Mackic will defend her doctoral thesis ‘Proving discriminatory violence at the European Court of Human Rights’. The defence will start at 15.00 hrs, at the Academy Building of Leiden University, Rapenburg 73. The supervisor of the research is Vice Dean and Professor of…

What influence did the internal debates on the use of violence within left-wing activist movements, and the government’s response to this (political) violence, have on the development, level, and continuity of the violence originating from these movements in the period 1965–2015?

To what extent is it possible to utilise traditional and new media data to examine and understand the nature and scope of homicide in Indonesia?

‘Violence as a Population Health Problem’ is one of 33 interdisciplinary projects that have been launched thanks to a Kiem grant. The project team will analyse a large patient database to identify links between violence and other health problems. ‘Violence can also be an expression of other factors,’…

Jeanine de Roy van Zuijdewijn, Chelsea Daymon and David Malet, wrote RESOLVE Network Research Report that examines career foreign fighters who have traversed from one insurgency to another.