Shifting sands: How change-point and community detection can enrich our understanding of international politics

When and how do international political arrangements change? International relations scholars have long examined the nature of shifts in international alliance and cooperation networks, often arguing that times of disruption in the international system are the most precarious for peace. In this research note, we rely on innovations in change-point and community detection methods to endogenously examine the timing and nature of shifts in country-to-country relationships through defense cooperative agreements. Using new methodical innovations from network science, we can see how countries move through different communities over time, changing the nature of polarity in the system. This empirical approach can help provide insights into determinants of peace, vulnerabilities in the international system, and potential aggressors in world politics.