Limited resources, access, and incomplete knowledge of weapons of mass destruction (WMD) threats create a need for working with appropriate partner countries around the world to address these challenging threats. This RAND National Defense Research Institute monograph outlines and then applies a four-step process for developing regional approaches to building partner capacity (BPC) to combat WMD. These steps include identifying capabilities and desired end states relative to the WMD threat, working with potential partners, identifying relevant BPC ways and means, and developing a framework to assess the effectiveness of BPC programs and activities. In doing so, the monograph identifies seven key themes that are linked to the recommendations. These key themes include improving guidance, increasing visibility of ongoing activities at a global level, improving coordination, encouraging collaboration, implementing procedures, conducting assessments, and securing resources.