Moscow's use of its military abroad in recent years has radically reshaped perceptions of Russia as an international actor. With the 2014 annexation of Crimea, the invasion of eastern Ukraine and sustainment of an insurgency there, and (in particular) the 2015 intervention in Syria, Russia repeatedly surprised U.S. policymakers with its willingness and ability to use its military to achieve its foreign policy objectives. Despite Russia's relatively small global economic footprint, it has engaged in more interventions than any other U.S. competitor since the end of the Cold War. In this report, the authors assess when, where, and why Russia conducts military interventions by analyzing the 25 interventions that Russia has undertaken since 1991, including detailed case studies of the 2008 Russia-Georgia War and Moscow's involvement in the ongoing Syrian civil war. The authors suggest that Russia is most likely to intervene to prevent erosion of its influence in its neighborhood, particularly following a shock that portends such an erosion occurring rapidly. If there were to be a regime change in a core Russian regional ally, such as Belarus or Armenia, that brought to power a government hostile to Moscow's interests, it is possible (if not likely) that a military intervention could ensue.