Of the many expectations attending the creation of the first permanent International Criminal Court, the greatest has been that the principle of complementarity would catalyse national investigations and prosecutions of conflict-related crimes and lead to the reform of domestic justice systems. Sarah Nouwen explores whether complementarity has had such an effect in two states subject to ICC intervention: Uganda and Sudan. Drawing on extensive empirical research and combining law, legal anthropology and political economy, she unveils several effects and outlines the catalysts for them. However, she also reveals that one widely anticipated effect – an increase in domestic proceedings for conflict-related crimes – has barely occurred. This finding leads to the unravelling of paradoxes that go right to the heart of the functioning of an idealistic Court in a world of real constraints.

‘This work gets under the skin of rules and institutions and looks with an acute anthropological eye at their real effects in practice. Under the rubric of complementarity, Sarah Nouwen has had the energy and courage to explore a difficult and variable terrain and the nerve to tell the resulting story. The result is a marvellous début.'

James Crawford - Whewell Professor of International Law, University of Cambridge

‘Complementarity is the International Criminal Court's admissibility pivot. Sarah Nouwen breathes life into what was, originally at least, a pleat of law and a fold of text. Nouwen courageously embraces humanity's frustrating ambiguities instead of conveniently overlooking them. Her work is lyrical and rigorous, poetic and poised, raw yet researched, granular but driven. For Nouwen, complementarity has spawned national law but has stymied national proceedings. Complementarity is mercurial - it offers, but it withholds, and then beguiles - and it also generates paradoxes - many of them - which Nouwen identifies and vivifies while, at the same time, she questions the self-evident triumph of international legalism. Much has been written about complementarity, to be sure, but Nouwen's voice is singular, path-breaking, and elegant. Her book is a must-read.'

Mark Drumbl - Class of 1975 Alumni Professor of Law, and Director, Transnational Law Institute, Washington and Lee University

‘Sarah Nouwen's work presents a rare combination of a genuine passion to empirically investigate and understand the ‘what is really going on' beyond preconceived patterns of effects, and a penetrating, analytic scholarly approach that reveals any easy postures in our thinking about today's international criminal justice.'

Immi Tallgren - University of Helsinki

'In her book, Sarah Nouwen presents a remarkable in-depth empirical analysis of the catalyzing effects of the principle of complementarity … With this book Sarah Nouwen does not only provide important ground-breaking work pertaining to the legal concept of complementarity but also reveals many misconceptions about this principle and gives a fascinating account of the catalyzing effects of complementarity in Uganda and Sudan.'

Gabriel M. Lentner Source: Vienna Journal on International Constitutional Law

'As a (legal) anthropologist I found it refreshing to read a scholarly work that asks how and whether legalisation of a conflict happens. While Nouwen demonstrates intimate knowledge of two very complex political situations, her analysis remains on the legal, institutional and discursive level.'

Source: The Journal of Modern African Studies

'… fascinating … Nouwen convincingly debunks the most common shibboleths about complementarity.'

Christian M. De Vos Source: The British Yearbook of International Law

'Nouwen’s analysis of the empirical record is incisive and thought provoking … this is a sophisticated study which significantly advances our understanding of how an ostensibly technical legal rule has transformed the debate about justice in societies riven by conflict.'

Patryk I. Labuda Source: Journal of International Criminal Justice

'… a tour de force … the book’s exposition is not only convincing and compelling, but admirably clear … rigorous, impressive, and important.'

Ronald R. Atkinson Source: Journal of International Humanitarian Legal Studies

'… an excellent exploration of the concept of complementarity under the Rome Statute of the International Criminal Court (the Rome Statute). In this book, Nouwen does not attempt a pure legal treatise. While she provides an excellent account of the legal dimensions of complementarity, she goes deeper, exploring sociological and political dimensions of complementarity and how it is used by various actors in the international criminal justice arena. Her findings, many of which are intuitive, are based on real empirical study and not just analysis of text. [This book] is well written, well-researched and adopts an objectivity that is often lacking in the literature on international criminal law, and the International Criminal Court (the ICC) in particular.'

D. Tladi Source: De Jure

'… this book is very essential for academics, researchers, practitioners and those in [a] position to influence domestic policies, by enabling them [to] appreciate the principle of complementarity and its catalyzing effects on domestic proceedings … Nouwen’s work is informative, interesting and greatly contributes to the study and practice of international criminal justice in domestic criminal jurisdictions.'

Saidat Nakitto Source: International Human Rights Law Review

'Over some five hundred pages and with a mammoth note apparatus, Complementarity in the Line of Fire will be a standard reference work on the International Criminal Court: massive in content and objective in analysis. … In assessing also Kwoyelo’s case in Uganda, parallel to Ongwen’s in The Hague, Nouwen shows that accountability is something much more profound than only bringing the culprits to the dock and making court proceedings public over the Internet. Anyone interested in how international justice and injustice unfold on the African continent must read Nouwen’s book.'

Sverker Finnström Source: African Studies Quarterly