Review of International Studies (2019), 45: 5, 711–730 doi:10.1017/S0260210519000184 RESEARCH ARTICLE . Populism and International Relations: (Un)predictability, personalisation, and the reinforcement of existing trends in world politics Sandra Destradi1* and Johannes Plagemann2 1Helmut Schmidt University / University of the Federal Armed Forces Hamburg and GIGA German Institute of Global and Area Studies and 2GIGA German Institute of Global and Area Studies *Corresponding author. Email:
[email protected] https://www.cambridge.org/core/terms (Received 29 November 2018; revised 2 May 2019; accepted 10 May 2019; first published online 18 June 2019) Abstract As populists have formed governments all over the world, it becomes imperative to study the conse- quences of the rise of populism for International Relations. Yet, systematic academic analyses of the inter- national impact of populist government formation are still missing, and political commentators tend to draw conclusions from few cases of right-wing populism in the Global North. But populism – conceptua- lised as a ‘thin’ ideology based on anti-elitism and anti-pluralism – takes different shapes across world regions as populists combine it with different ‘thick’ ideologies. To reflect such diversity and gain more systematic insights into the global implications of populism, we focus on cases of populist government formation in the Global South. We find that populists in power are not, per se, more belligerent or less willing to engage globally than their non-populist predecessors. Factors like status seeking or a country’s embeddedness in international institutions mitigate the impact of populism. Its most immediate effect concerns procedural aspects: foreign policymaking becomes more centralised and personalised – yet, , subject to the Cambridge Core terms of use, available at not entirely unpredictable, given the importance of ‘thick’ ideologies espoused by populist parties and leaders.