Many security cooperation activities are predicated on the assumption that interactions between American and foreign military personnel can drive broader behavioral and institutional changes within partner militaries and governments. For instance, international military training and education programs provide sustained engagement between U.S. and foreign service members, offering opportunities to share U.S. approaches to national defense alongside American values, interests, and institutional practices. However, frequent turnover of personnel and the inherent complexity of partners’ political systems and military bureaucracies raise questions about the causal significance of individuals and their relationships. While there are countless anecdotal examples of relationship-building programs yielding positive, neutral, or even negative results, there is limited evidence of the nuanced effects that shared values, trust, and intellectual interoperability may have in enhancing burden sharing and of approaches to advising, training, and educating individuals that might generate institution-level change