Biography and research interests

Samuël Kruizinga (1980) is associate professor of War Studies and Modern History at the University of Amsterdam (UvA). He studied at Leiden, Paris and Oxford, and has held fellowships at Trinity College Dublin, Oxford University, and the European University Institute. Trained as an historian (PhD 2011), his work has been deeply influenced by insights from the political, social and economic sciences, as well as war and strategic studies and the digital humanities. Interdisciplinary by nature, his research focuses on conflict, conflict resolution, and resilience to shocks and crises in modern Europe and beyond. In recent years, that research has focused on two overarching themes. The first is slow violence: forms of violence that are not spectacularly explosive (like a battle in a war) but operate on a much longer time scale, and are therefore less visible but no less harmful. The second is grey zones: spaces, either temporal, geographical, or ideational, between the extremes of war and peace. Those two themes are central to his research on occupations in the First and Second World Wars, on forms of conflict in the space between the philosophical and legal extremes of war and peace (grey zone warfare), on foreign fighting in the 20^th and 21^st centuries (including in Ukraine) and on sanctions and economic blockades in the 20th century.

Kruizinga contributed to successful funding applications worth, in total, more than 18 million euros, is currently PI in both an ERC and a Netherlands Research Council (NWO) sponsored project.

He has (co)-written numerous books and articles and (co-)edited volumes and special issues of journals. His work has appeared in multiple languages, including English, French, German, Czech, and Chinese, and in leading academic journals, including European review of history, War in History, European History Quarterly, Contemporary European History, and The International History Review. He is currently co-writing, with Prof Sophie De Schaepdrijver, a book on the occupation of Brussels during the First World War to be published with Cambridge University Press, and, with Prof Marco Wyss, a book on grey zone warfare in past and present, to be published with Oxford University Press.

Current project: The Hidden Weapon. Blockade in the Era of the Two World Wars (ERC SYNERGY)

The main aim of BLOCKADE is to investigate how blockades shaped the era of the world wars, c. 1900-1960. In both wars, belligerents sought to blockade the enemies, cutting them off from vital supplies such as food, oil, and capital, while maintaining their own access to them. Existing research is patchy, contradictory and Eurocentric. Basic issues as to the blockade’s scope, reach and effects on the wars’ outcomes and aftermaths are unresolved. BLOCKADE thus addresses a major knowledge gap.

Our hypothesis is that the blockades were in fact critical to the era. They affected societies the world over, testing their resilience and vulnerability; they produced new forms of violence and humanitarian care; they prompted innovation and learning; and they had integrative and disintegrative effects on wartime societies, alliances and the world order. The project’s ambitious global approach transcends the traditional fixation on western Europe. It connects the disparate histories of the First and Second World Wars in a single explanatory frame by uncovering the shared generational experiences and learning processes related to blockades. It thus promises a new analytical framework to interpret the era, integrating actors long seen as ‘peripheral’, e.g. neutral countries and colonial territories. These insights will break the mould of existing historiography and involve the high risk that we might fail to separate the impact of blockade from other effects of warfare. Russia’s invasion of Ukraine in 2022, with the reemergence of blockade and worldwide scarcities, underlines the contemporary relevance of the project.

This ERC SYNERGY (ERC 2024 SyG 01166983) project is collaborative in nature: I work closely together with fellow PIs Prof. Jonas Scherner (NTNU Norway), Prof. Alan Kramer (Universität Hamburg), and Dr Elisabeth Piller (Albert-Ludwigs-Universität Freiburg). A first, tangible result will be a special issue on the topic with the International History Review.

For more information on our project, see our website.

Research project: Occupied Brussels, 1914-1918

On August 20, 1914, the imperial German armies seized Brussels, the capital of Belgium, marking the beginning of a fifty-month military occupation. This book explores the experiences and perspectives of the people of Brussels, the largest occupied capital of the First World War, alongside Warsaw. It examines the lives of the occupied citizens, the German officials and officers, and the citizens of neutral countries who provided humanitarian aid, conducted business, or reported on the situation.

Brussels held significant importance during the war, symbolizing the conflict's core issues. Germany's invasion of neutral Belgium violated international law and led to global propaganda over war crimes. Belgium became a focal point for world public opinion, with the Allies defending Belgium as a just cause, emphasizing the international rule of law. The US and other neutrals provided substantial relief aid, and upon entering the war in 1917, the US revived German-atrocity rhetoric.

The book highlights Brussels as the center of Belgian national sentiment and war efforts. The Allies, Belgian government in exile, and Belgian monarch closely monitored events in the city. The US-led global aid program operated under the protection of diplomats based in Brussels, while the Belgians' own relief organization devised welfare programs. For the Germans, Brussels was a showcase for their cause, demonstrating stern but just rule and engaging in nation-building for Belgium's Flemings.

The bruxellois played a vital role in global understandings of the war, expressing their experiences through hidden diaries, underground newspapers, and satirical prints. Despite the specter of extreme violence, Brussels saw no civilian massacres but experienced various forms of violence, including military court sentences, forced labor, deportation drives, malnutrition, and psychological tolls. Allied aerial bombings added to the trauma.

The occupied urban society demonstrated resilience, with a functioning civil society, local administration, and global social capital. The book maps the city's resilience, networks, methods, discourse, and results, while acknowledging failures and social injustices. The German occupation of Brussels was not a story of overwhelming force, but rather a dance with a bully, leaving both sides exhausted, proud, and bitter in equal measure.

Together with Sophie de Schaepdrijver (Penn State) I have secured contracts for this book with and Cambridge University Press and Overamstel Uitgevers / Horizon (for a version in Dutch). Research for the book has been made possible thanks to grants from the Cultuurfonds and the Van Winter Fonds.

Current project: Grey Zone Warfare in Past, Present, and Future (AHRC Networking Grant)

'Grey zone warfare' emerged as a key strategic global challenges in 2014. Russian operations in Ukraine, which were not part of any declared or easily recognisable form of warfare, confounded academics, pundits, politicians and Western armed forces. This and other conflicts in the 'grey zone' somewhere between war and peace were then described by a host of 'proto-concepts': 'new wars', low-intensity conflicts, operations other than war, fourth-generation warfare, hybrid warfare, and, indeed, 'grey zone warfare', whose one common denominator was that warfare had changed. Gone were the days of 'modern warfare', the domain of uniformed men fighting pitched battles to achieve decisive victories. Replacing them was 'post-modern' fluidity and diffusion, an erosion of traditional distinctions between war and peace, protracted struggles for 'hearts and minds', an almost limitless spectrum of violence, and a large toolbox ranging from proxy militias to cyber warfare with the wide-ranging objective of destabilising adversaries.

This project, however, is founded on the notion that history is rife with conflicts that have more in common with 'Ukraine' - or, indeed, 'Afghanistan' - than with the supposed norm of 19th and 20th-century regular, i.e. European, warfare. Our network innovates by positing that grey zone warfare is the most suitable analytical term to capture the key element connecting both 'post-modern' and other forms of conflict outside the Eurocentric 19th and 20th-century norm: organized violence existing between the states of declared interstate war and peace. A global, longue durée historical approach allows us to include in our analyses of grey zone warfare a diverse range of cases, ranging from sieges in medieval Europe to the Sino-Japanese proxy war over Korea in the 19th century. Yet, grey zone warfare is an essentially contested concept, lacking clearly defined parameters.

We thus aim to provide conceptual clarity by studying various forms of warfare that do not fit the European norm of state-based conflict, and to create a typology of 'grey zone warfare'. In drawing on representative historical case studies, we will identify their underlying dimensions, create and discuss categories for classification, measure and sort them, map variations, and, ultimately, provide important conceptual building blocs. Global in scope and collaborative in nature, this project will create a network of scholars from a variety of disciplines – ranging from History to IR to Security Studies – to collaborate, compare and contrast different cases in order to jointly create a typology of grey zone warfare. The results will then be analysed and assessed in comparison to current relevant military strategies and doctrines, with the aim of critiquing and/or adding to those based on relevant historical examples. This will add important new ideas and data to both current scholarly approaches to grey zone warfare, the curricula of military academies, doctrinal manuals, policy on both the tactical, operational and strategic levels, and increase public understanding of the complexities of the grey zone phenomenon.

This project, in collaboration with professor Marco Wyss (Lancaster University), is funded by the Arts and Humanities Research Council, AH/W01128X/1)

Current project: Foreign Fighters in Ukraine (NWO)

Since the Russian invasion of Ukraine of 24 February 2022, tens of thousands of volunteers from 52 different countries – including at least 200 Dutchmen – have joined Ukraine’s “International Legion”. These ‘foreign fighters’ are, however, not the first to voluntary join a fight in a country they were not native to or citizens of. Precedents include the Zouaves who supported the Pope in his fight against Italian nationalists (1860-1870), the International Brigades fighting a Nazi-backed insurgency in Spain (1936-1939), and the foreign fighters who flocked to Syria and Iraq in support of the Islamic State (2012-2016). Only very recently have the first attempts been made to connect some of these separate historical instances of foreign fighting, and a burgeoning debate has begun over what sets these fighters apart from other violent actors, and what effects they have on both host and home countries. The emergence of the “international Legion” has increased the urgency of questions, especially since their members’ legal status remains deeply contested, they are likely to endure or be active participants in extreme violence, and will receive no official support readjusting to civilian life and/or deal with trauma or moral injury. Moreover, it is very likely this foreign fighter mobilisation will not be the last.

This project seeks to better understand the foreign fighting phenomenon, which continues to confound policy makers and poses manifold challenges to both ‘peace’, both in foreign fighters’ home and host countries. By adding unique new source material to our study of foreign fighting, this project will not only aid to scientific understanding of current events, but also past and future instances of foreign fighting by together various disciplines including history, law, and psychiatry. Societal stakeholders are ARQ45, the Dutch national centre for specialist diagnostics and treatment of people with complex psychotraumatic complaints, and the T.M.C. Asser Institute which specialises in international law and operates at the interface of academia, legal practice and governance.

This project is funded by the Dutch National Research Agenda (Nationale Wetenschapsagenda, NWA.1418.22.005).

Teaching and thesis supervision

I am available for (BA, MA and PhD) thesis supervision on any topic related to my research interests. Do not hesitate to e-mail me and make an appointment to discuss your (future) plans.

In my teaching and supervision, I emphasise active student engagement through outcomes-based teaching, which are constructively aligned at both the programme and the course level. In general, my teaching is highly valued by students, as evidenced by exceptionally high evaluation scores.