External sanctions are one of the most commonly used foreign policy tools to confront states’ undesired behavior and to support democracy as well as human rights. The literature has recurrently identified the impact of sanctions on domestic opposition movements as crucial for such measures’ effectiveness. Yet, sanctions research still lacks a detailed understanding of the processes leading to the so-called internal opposition effect of international sanctions. Accordingly, this dissertation examines how and under which conditions domestic opposition is enabled by external sanctions. To address this question, a theoretical framework that integrates insights from two strands of literature that have not been systematically brought together thus far, sanctions research and social movement theory, is developed. In addition to traditional deprivation-based and political opportunity approaches for studying domestic contestation, it highlights how sanctions’ signals of regime disapproval and opposition support create perceived opportunities for the voicing of dissent, particularly if communicative linkages between the sanctions senders and the targeted states’ societies exist. In contrast to earlier studies, the hypotheses delineate the interplay of these explanatory approaches instead of understanding them as competitive. Empirically, the dissertation employs a multi-method research design that integrates fuzzy set Qualitative Comparative Analysis (fsQCA), process tracing and structured, focused comparison in an epistemologically coherent way. First, an fsQCA is conducted on the basis of a comprehensive database that covers all 75 EU, US, UN and regional sanctions regimes imposed on Sub-Saharan African countries between 1990 and 2012. Four combinations of conditions that lead to an increase in anti-government activity in regimes under sanctions are identified. In addition to confirming previous knowledge about the importance of deprivation, linkage, and a minimum degree of political openness for anti-regime mobilization, a novel mechanism highlighting the interplay of sanctions’ socio-economic consequences and signals is identified. The analysis passes five fundamental robustness checks. Second, two process-tracing analyses serve to reconstruct the causal mechanisms behind the novel configuration, which inter alia explains the trajectory of the opposition movements in Burundi and Zimbabwe according to the fsQCA. The case studies are based on a total of 79 elite interviews conducted during field research in both countries and additional document analyses. The case of Burundi confirms that signals of regime disapproval encourage anti-regime actors domestically. However, sanctions failed to instigate popular mobilization through the creation of socio-economic hardship because regime-critical forces lacked organizational capacities and key constituencies were shielded from the embargo’s adverse financial consequences. The Zimbabwe case study also shows that the sanctions’ signals of support for protestors and the major opposition party MDC motivated regime-critical actors. As regards the deprivation-based explanation, how the opposition framed the sanctions’ socio- economic repercussions rather than their ‘tangible’ effects appear to be the crucial mechanism. Third, the two case studies are contrasted through a structured, focused comparison, which demonstrates how the power-sharing agreements signed both in Zimbabwe and Burundi affected the sanctions’ signaling dimension. Most importantly, power-sharing agreements (re- )legitimize the incumbent regime and thereby undermined the signals of regime disapproval conveyed by sanctions. Moreover, sanctions succeeded in encouraging the broader population in Zimbabwe, where strong societal ties to the sanctions senders exist, whereas the message of regime disapproval and opposition support only reached the well-connected political elite in Burundi. The dissertation concludes by critically reflecting its limits and the findings’ generalizability. Finally, policy implications are sketched. To convey coherent signals, coordination among sanctions senders as well as between different foreign policy instruments and monitoring the domestic sanctions discourse within the targeted regime are of key importance.
