Tobias Böhmelt

Environmental changes and violent conflict

This letter reviews the scientific literature on whether and how environmental changes affect the risk of violent conflict. The available evidence from qualitative case studies indicates that environmental stress can contribute to violent conflict in some specific cases. Results from quantitative large-N studies, however, strongly suggest that we should be careful in drawing general conclusions. Those large-N studies that we regard as the most sophisticated ones obtain results that are not robust to alternative model specifications and, thus, have been debated. This suggests that environmental changes may, under specific circumstances, increase the risk of violent conflict, but not necessarily in a systematic way and unconditionally. Hence there is, to date, no scientific consensus on the impact of environmental changes on violent conflict. This letter also highlights the most important challenges for further research on the subject. One of the key issues is that the effects of environmental changes on violent conflict are likely to be contingent on a set of economic and political conditions that determine adaptation capacity. In the authors’ view, the most important indirect effects are likely to lead from environmental changes via economic performance and migration to violent conflict.

One effect to rule them all? A comment on climate and conflict

A recent Climatic Change review article reports a remarkable convergence of scientific evidence for a link between climatic events and violent intergroup conflict, thus departing markedly from other contemporary assessments of the empirical literature. This commentary revisits the review in order to understand the discrepancy. We believe the origins of the disagreement can be traced back to the review article’s underlying quantitative meta-analysis, which suffers from shortcomings with respect to sample selection and analytical coherence. A modified assessment that addresses some of these problems suggests that scientific research on climate and conflict to date has produced mixed and inconclusive results.

Coup-Proofing and Military Effectiveness in Interstate Wars, 1967–99

This study examines the influence of civil–military relations on military effectiveness. More specifically, we investigate how coup-proofing, that is, the strategies and tactics employed to prevent the military from seizing power, affects battlefield performance. The main argument claims that coup-proofing has a negative impact on soldiers’ leadership qualities, initiative, and the ability to coordinate different military units. Ultimately, the higher a country’s coup-proofing efforts relative to its opponent, the worse its effectiveness on the battlefield. We test this hypothesis using data on battlefield outcomes and coup-proofing between 1967 and 1999.

Do natural resources matter for interstate and intrastate armed conflict

This article reviews the existing theoretical arguments and empirical findings linking renewable and non-renewable natural resources to the onset, intensity, and duration of intrastate as well as interstate armed conflict. Renewable resources are supposedly connected to conflict via scarcity, while non-renewable resources are hypothesized to lead to conflict via resource abundance. Based upon our analysis of these two streams in the literature, it turns out that the empirical support for the resource scarcity argument is rather weak. However, the authors obtain some evidence that resource abundance is likely to be associated with conflict. The article concludes that further research should generate improved data on low-intensity forms of conflict as well as resource scarcity and abundance at subnational and international levels, and use more homogenous empirical designs to analyze these data. Such analyses should pay particular attention to interactive effects and endogeneity issues in the resource–conflict relationship.

The temporal dimension of the credibility of EU conditionality and candidate states’ compliance with the acquis communautaire, 1998–2009

Existing research seems to agree that European Union (EU) accession conditionality facilitated processes of political and economic transformation for the recent enlargement rounds. However, despite its importance, systematic research beyond small-N qualitative studies that produces generalizable insights is scarce. Most strikingly, it remains unclear at which stage of the enlargement process and to what extent candidate countries complied with EU law in the context of accession conditionality. Building upon previous theoretical accounts, the authors argue that candidates’ compliance behaviour can be examined more thoroughly when focusing on the credibility of EU conditionality at different phases over the process of accession negotiations, which are characterized by varying degrees of membership probability. The article’s main contribution stems from the empirical analysis, which employs generalized additive models on new data of candidate countries’ compliance with EU law under accession conditionality from 1998 to 2009.

The Impact of Institutional Coup-Proofing on Coup Attempts and Coup Outcomes

Coup-proofing pertains to political leaders’ strategies that will prevent groups inside or outside the state apparatus from seizing power via a coup d’état. One particular form of these strategies divides a country’s military into rivaling organizations, thereby creating an artificial balance between and structural obstacles for the armed forces. Despite the general claim that this institutional coup-proofing is indeed effective, a recent empirical study does not obtain evidence for a negative impact on the risk of coup attempts or coup outcomes. The authors take this finding as a motivation for their re-evaluation of the effect of institutional coup-proofing on coup risk and outcomes. By developing an argument that rests on the concepts of collective action and polarization, it is contended that institutional coup-proofing and coups are characterized by a U-shaped relationship: Institutional coup-proofing is likely to lower the likelihood of coup onsets and successful outcomes, yet only until a tipping point of about two equally strong military organizations. After this turning point, the risk of coup onset as well as coup success may increase again. Using time-series cross-section data for 1975–1999, the authors find strong and robust support for their claims in terms of coup onset, but not coup outcomes.

The effectiveness of tracks of diplomacy strategies in third-party interventions

International mediation is not conducted solely by official actors such as states or international organizations. Non-official parties such as individuals and non-governmental organizations increasingly intervene as third-party mediators in conflicts. Both official and unofficial interventions are conceptualized as tracks of diplomacy (ToDs). Even though there is a vast quantitative literature on international mediation, most studies focusing on ToDs have been qualitative and produced few generalizable insights. This article extends the existing literature on third-party intervention by developing a theoretical model to explain the effectiveness of different ToDs, which is then empirically tested in a first large-N study. The findings indicate that the leverage and resources of ToDs determine outcome effectiveness. Track One Diplomacy, that is, efforts by official actors, tends to be the most effective form of intervention as greater leverage and more resources invested can make track intervention more effective. It is also found that combined mediation efforts of both official and unofficial tracks can be more effective than independent track actions. Since conflicts with mediation are unlikely to be a randomly selected set, a selection estimator is used to test the hypotheses on effectiveness. The empirical findings support the theory and demonstrate that the specific type of mediating actor seems highly important.

Water-Related Intrastate Conflict and Cooperation (WARICC): A New Event Dataset

Water scarcity is widely regarded as a key factor linking climate variability and change with conflict. However, existing research on the water-conflict nexus is hampered by poor data that inhibits drawing firm conclusions on the role of water in shaping societal stability and security. This article reports on the construction of a new dataset on subnational and georeferenced events over domestic water-related cooperation and conflict for 35 countries in the Mediterranean, the Middle East, and the Sahel for 1997–2009. The main value of this dataset is in its precision. Its key component, the Water Events Scale (WES), records the exact time, location, and intensity of water-related conflictive and cooperative events, as well as the actors involved. A few descriptive statistics and illustrations serve to demonstrate the usefulness of the new dataset for quantitative analyses of intrastate conflict and cooperation over water resources.

The impact of environmental interest groups in international negotiations: Do ENGOs induce stronger environmental commitments?

Although there is a substantial amount of research that studies how environmental interest groups/non-governmental organizations (ENGOs) influence international environmental negotiations, both the theoretical work and the empirical evidence were not yet able to answer comprehensively if this makes it more likely that states, in turn, commit to stronger environmental agreements. This article seeks to contribute to clarifying this. First, the authors argue that a higher degree of ENGO access to official negotiations and a larger number of ENGOs actively participating during bargaining processes can facilitate outcomes of environmental negotiations. The authors then analyze quantitative data on international environmental regimes and their members’ commitment levels from 1946 to 1998 and obtain robust support for their claims. However, the rationale on the introduced explanatory factors also implies that the impact of ENGO access on states’ commitment levels should vary conditional on the number of ENGOs actively participating. The paper finds evidence for such an interaction, although the results go against our expectations.

Does Immigration Induce Terrorism

There is a heated debate on whether immigration is associated with domestic and transnational terrorism. As of yet, however, we lacked rigorous evidence that could inform this debate. As a contribution to address this shortcoming, we report spatial-econometric analyses of migrant inflows and the number of terrorist attacks in 145 countries between 1970 and 2000. The results suggest that migrants stemming from terrorist-prone states moving to another country are indeed an important vehicle through which terrorism does diffuse. Having said that, the findings also highlight that migrant inflows per se actually lead to a lower level of terrorist attacks. This research significantly improves our understanding of international and domestic terrorism and has critical implications for the scholastic approach to terrorism, as well as for countries’ immigration policies worldwide.