This research note summarizes version 3.0 of the Correlates of War Direct Contiguity data set, which covers the geographic proximity of all directly contiguous states in the international system during the period 1816-2000. After a brief discussion of the role that geographic proximity plays in international relations, the coding rules and procedures used for this data set are reviewed. The changes and additions to this updated version of the data are then explained. This note concludes with a basic statistical summary of the updated data set

Although the subject remains contested, some have speculated that climate change could jeopardize international security. Climate change is likely to alter the runoff of many rivers due to changes in precipitation patterns. At the same time, climate change will likely increase the demand for river water, due to more frequent droughts and greater stress being placed on other sources of water. The resulting strain on transboundary rivers could contribute to international tensions and increase the risk of military conflict. This study nevertheless notes that the propensity for conflicts over water to escalate depends on whether the river in question is governed by a formal agreement. More specifically, the article argues that the ability of river treaties to adapt to the increase in water stress resulting from climate change will depend on their institutional design. It focuses on four specific institutional features: provisions for joint monitoring, conflict resolution, treaty enforcement, and the delegation of authority to intergovernmental organizations. Treaties that contain more of these features are expected to better manage conflicts caused by water stress. This expectation is tested by analyzing historical data on water availability and the occurrence of militarized conflict between signatories of river treaties, 1950–2000. The empirical results reveal that water scarcity does increase the risk of military conflict, but that this risk is offset by institutionalized agreements. These results provide evidence, albeit indirect, that the presence of international institutions can be an important means of adapting to the security consequences of climate change by playing an intervening role between climate change and international conflict.

Despite the importance of enduring rivalries, to date little attention has been placed on understanding how they develop. This article presents one of the first attempts to understand rivalry development. Two broad approaches to protracted rivalry development, behavioral and structural, are contrasted. The behavioral approach focuses on the actions of the potential rivals during their early confrontations, and argues that initial behavior will establish the direction of future interactions. The structural approach proposes that rivalries are caused by environmental factors largely out of the immediate control of the participants. When tested, we find that the development of proto and enduring rivalries can be explained best by a combination of both approaches. We also find that longer term rivalries do not appear to have one single cause. They may instead be produced by the confluence of many small factors.

International agreements governing rivers vary considerably in whether they contain institutional provisions for joint monitoring, conflict resolution, enforcement, and/or the delegation of authority to intergovernmental organizations. This article develops an explanation for why some river management treaties include more institutional provisions while others contain fewer, if any. The authors argue that certain types of issues related to river use-water quantity, water quality, and navigation-tend to be difficult to manage and prone to noncompliance. When forming treaties to address these specific issues, states will be more likely to include institutional provisions. The authors test the link between these river use issues and institutional design using a data set of 315 river treaties signed since 1950. The results show that highly contentious issues-and in particular water quantity and navigation-have a greater effect on the institutional design of river treaties than contextual and power politics factors.Population growth, pollution, economic development, and climate change are putting increasing strain on the earth's rivers. The fact that international river basins cover roughly 47 percent of the world's surface (Wolf 2007) suggests that the use

The adoption of UN Security Council Resolution (UNSCR) 1540 in 2004 reflects an emerging consensus that more should be done by the international community to address the proliferation of weapons of mass destruction. UNSCR 1540 articulates a universal, legally binding obligation for all states to confront proliferation by adopting effective export control systems. To date, however, there have been no attempts to systematically analyze compliance with this new obligation, making it impossible to assess the success of this measure and the underlying causes of any shortcomings. This study addresses this by conducting a systematic empirical analysis of state compliance with UNSCR 1540. Drawing upon theories of compliance with international law, we investigate two distinct explanations for variation in the degree to which states adopt nonproliferation export controls: one based on state interests and enforcement and the other based on state capacity. Our statistical tests of these theories use a new, cross-national data set detailing the nonproliferation policies of 30 states. The empirical results indicate that compliance with international nonproliferation obligations is influenced most by a state's economic and governmental capacities and has little to do with interest-based factors. These findings suggest that capacity-building programs are the best option for improving the implementation of UNSCR 1540 and of nonproliferation efforts in general.