This thesis examines how political conflict in Yemen has played out within the country’s diplomatic corps since 2011. Drawing on nine months of fieldwork, it analyses the complex interplay of socio-political, personal, and material forces that informed the maintenance and partial reworking of Yemeni foreign policy institutions at a time of crisis. It argues that the coexistence of institutional endurance and change constitutes a paradox that can only be grasped by conceptualizing the Yemeni foreign service as a dynamic, fragmented, and internally uneven socio-material institution. It finds that institutional boundaries are highly permeable, allowing broader socio-political changes to impact internal institutional developments. In the Yemeni diplomatic service, regime change and war translated into a particular professional challenge, marked by shifting and diversified diplomatic practices, attitudes, forms, and functions. Notwithstanding such change, strands of continuity prevailed, rooted in material institutional structures, as well as staffing policies, professional norms, and personal thoughts and emotions. In the process of examining internal change and continuity, this thesis sheds light on the controversial yet central notions of diplomatic loyalty and professionalism, while further fleshing out the concept of diplomatic agency, which is shown to underlie both revolutionary and counter-revolutionary processes. This study challenges the Western-centric bias in contemporary diplomacy research and constitutes an important step toward a radically heterogeneous imagination of diplomats and diplomatic practice. Its empirical insights unsettle widespread perceptions of global diplomacy as a homogeneous professional field marked by bounded state interests, material luxury, and shared professional conduct. This thesis also adds to the multidisciplinary field of state theory, using the case of the Yemeni foreign service to explain the historical entanglement of diplomacy, international recognition, sovereignty, and a government’s successful claim to “statehood”.