On the transformation of warfare: a plausibility probe of the new war thesis Monika Heupel a and Bernhard Zangl b a Social Science Research Center Berlin (SSRCB), Research Unit Transnational Conflicts and International Institutions, Reichpietschufer 50, 10785 Berlin, Germany. E-mail: heupel@wzb.eu b LMU Munich, Geschwister-Scholl-Institute of Political Science, Oettingenstr 67, 80538 Munich, Germany. E-mail: Bernhard.Zangl@gsi.uni-muenchen.de This article intends to contribute to the debate on the emergence of so-called new wars by reconstructing the new war thesis in a way that allows an empirical assessment of the plausibility of the thesis. It makes explicit the defining criteria implicit to the new war thesis which claims that a fundamental transformation of modern intra-state warfare has taken place due to the end of the Cold War. It also lays out the causal mechanisms that underpin the alleged transformation of warfare. Based on the reconstructed conceptual framework and drawing on case studies of the wars in Cambodia, Afghanistan, Angola, Somalia and Sierra Leone, the article then lends support to the new war thesis. The cases demonstrate that, in the 1990s, war economies based on criminal activities became more important and triggered the fragmentation of warring parties and the economisation of their war motives. Moreover, in combination, the fragmentation of warring parties and the economisation of their war motives facilitate the application of brutal violence against civilians. Journal of International Relations and Development (2010) 13, 26–58. doi:10.1057/jird.2009.31 Keywords: civil war; new wars; peace research; transformation of warfare; war economy; warlords Introduction Contrary to predictions of some neorealists, the end of the Cold War did not take us ‘back to the future’ of the great power wars (Mearsheimer 1990). The transformation from a bipolar to a multipolar distribution of power did not give rise to great power struggles of the kind that had characterised the pre- 1945 era. At the same time, unlike the expectations of some Liberals, the democratisation of many states after the Cold War did not bring global peace and the ‘end of history’ (Fukuyama 1989). Yet, the end of the Cold War did coincide with a considerable decline in global warfare. While the incidence of Journal of International Relations and Development, 2010, 13, (26–58) r 2010 Macmillan Publishers Ltd. 1408-6980/10 www.palgrave-journals.com/jird/