Joint, Interagency, Intergovernmental and Multinational (JIIM) organizations participate in the Theater Security Cooperation environment. Each of these organizations’ roles and responsibilities contribute to a holistic approach in the development of defense relationships. The Theater Security Cooperation environment is complex and plagued by disparities in terminology, doctrine, and policies of the U.S. military and interagency organizations, as well as those of our partner nations. These issues create interoperability gaps that impede their ability to synchronize actions and ensure complementary efforts are occurring to achieve unity of effort and action. This paper will analyze the various directives and publications to develop an understanding of the goals of security cooperation, the key organizations involved in security cooperation at the various levels of control, the roles and responsibilities of these organizations, and how these organizations contribute to the holistic approach to security cooperation. Lastly, the paper will provide recommendations on ways to better integrate organizational efforts to increase JIIM interoperability in the security cooperation arena and follow-on unified actions.