Combining scholarship on norms and trust in International Relations, this article puts forward the concept of entrusted norms as a novel means to understand certain dynamics of cooperation and conflict in international politics. Entrusted norms differ from non-entrusted norms both in the manner that they are policed and in the reaction to their infringement. In the first case, there are few formal hedging mechanisms taken against potential defection. In the second case, when broken, they result in a betrayal reaction where a return to the behavioral status quo is insufficient to return to the political status quo. We illustrate the analytical usefulness of entrusted norms through an examination of the established norms of diplomacy within the Gulf Cooperation Council, paying particular attention to interactions between Saudi Arabia and Qatar in the post-Arab Spring period. We argue that the perception of Qatar’s defection from an entrusted norm, the preservation of individual and collective dignity, contributed to the 2014 diplomatic rupture between these two states and set in motion a betrayal/attempted reconciliation cycle, where even Qatar’s attempts to move back to the behavioral status quo prior to the fallout have been insufficient to fully repair the relationship. In addition to providing a novel interpretation to this case, this paper highlights the need for further theoretical consideration of the severity and duration of punishment after norm transgression within social constructivism, reinforces the theoretical connection between social structures and emotions, and advocates for an expansion in the domains of trust that we study.