I study the domestic politics of international security: why democracies differ in military involvement, how parliaments and parties shape decisions on the use of force, and how foreign policy shifts under geopolitical change, most recently Germany’s Zeitenwende and European responses to Russia’s war against Ukraine. At VU Amsterdam I lead the work package on foreign-policy contestation in the NEST project, where we surveyed attitudes on military assistance in the Netherlands and across Europe in 2025.
My methodological work focuses on Qualitative Comparative Analysis (QCA) as a set-theoretic method for descriptive and causal inference. My books include Democratic Participation in Armed Conflict and Qualitative Comparative Analysis: An Introduction to Research Design and Application, and I’m co-editor of the Routledge Handbook of Foreign Policy Analysis Methods.
You can find my publications, research projects, and CV on this site. Please feel free to reach out.
Upcoming
- 7–9 December 2026
European QCA Conference, IHS, Erasmus University Rotterdam - December 2026 / January 2027
Registration opens for the QCA course at the Lugano Summer School (August 2027, pending confirmation)
Latest updates
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Ten Years of QCA at the Lugano Summer School
For the eighth time, I taught “Exploring Causal Complexity with Qualitative Comparative Analysis (QCA)” at the Summer School in Social Sciences Methods in Lugano, ten years after the first edition of the course. The intensive one-week course combines lectures with hands-on exercises in R, participant presentations and individual consultations. Continue reading →
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R Manual for QCA, version 4.1
Version 4.1 of the R Manual for QCA adds expanded sections on visualizing results, with templates for creating, customizing and combining X–Y plots, along with new sections on cluster analysis and robustness tests following the protocol of Oana and Schneider. The manual now runs to 44 pages, with an accompanying R script and sample data. Continue reading →
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Uncovering Causal Symptoms Discussed at AQMMR workshop
Hilde van Meegdenburg and I presented our co-authored book manuscript “Uncovering Causal Symptoms: Case Study Research, Process Tracing, and Qualitative Comparative Analysis” at the AQMMR workshop of the Institute for Qualitative and Multi-Method Research at Syracuse University, where it was discussed by James Mahoney and Ingo Rohlfing. Continue reading →
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Article in Public Policy and Administration
“Can the Public Sector Break the Mold?” is out in Public Policy and Administration, co-authored with Alessia Caputo, Lorenzo Taddeucci and Milena Vainieri. Using fuzzy-set QCA and data from 26 Tuscan health districts, we examine the conditions under which public organizations develop sensing capabilities and organizational adaptability. Continue reading →