Before joining VU Amsterdam in 2022, I completed my Habilitation at the Technical University of Munich (2020), obtained my PhD at Humboldt-Universität zu Berlin (2012), and held research and teaching positions in Munich, Dresden, and Erfurt, including the interim Franz Haniel Professorship for Public Policy (2017–18). For details on appointments and education, see my CV.

I work on the domestic politics and politicization of international security: why democracies differ in their involvement in military operations, how parliaments and political parties shape decisions on the use of force and military assistance, and how foreign policy changes, most recently in work on Germany’s Zeitenwende and European responses to Russia’s war against Ukraine. My second area of research is methods-related, focusing on Qualitative Comparative Analysis (QCA) as a set-theoretic method for descriptive and causal inference. I am particularly interested in multi-method research design, especially on combining QCA and process tracing for cross-case and within-case inference.

My books include Democratic Participation in Armed Conflict: Military Involvement in Kosovo, Afghanistan, and Iraq (Palgrave Macmillan, 2014), which received the Best Dissertation Award of the German Political Science Association, and Qualitative Comparative Analysis: An Introduction to Research Design and Application (Georgetown University Press, 2021, with a second edition under contract), translated into Japanese as 質的比較分析 (QCA): リサーチ・デザインと実践 (Chikura Publishing, 2023). I am also the co-editor of the Routledge Handbook of Foreign Policy Analysis Methods (2023).

I am involved in professional associations and I am an editorial board member of International Studies Quarterly, Foreign Policy Analysis, and Contemporary Security Policy (see Service page).