Climate change is projected to affect the physical environment of the U.S. Central Command (CENTCOM) area of responsibility (AOR) significantly throughout the 21st century and could have consequences for security. How climate change might do this, and what these security consequences might be, are important issues for security planners. U.S. competitors and adversaries could have new opportunities to seek advantages relative to the United States. To understand how China, Russia, and Iran might exploit climate-related conflicts, the RAND Corporation hosted a two-day workshop that presented nine scenarios with different climate hazards and levels of conflict to a panel of 11 subject-matter experts. The experts were knowledgeable about the overall global strategy, interests, and capabilities of China, Russia, and Iran and were asked to assess how these countries would react to climate-related conflict. This report provides the results of that workshop. The purpose of this research is to support CENTCOM leadership and planners and their interagency partners to prepare for a future security environment that is affected by climate change. Understanding the frequency of future conflict in the AOR, as well as the evolution of threats under climate change, will enable the U.S. government to better prepare for this future. This report is the fourth in a series focused on climate change and the security environment.