This article addresses critical gaps in the literature on crisis-driven policy change in international organisations. While existing studies focus on elite decision-making and institutional resilience, the role of frontline crisis managers remains under-explored in International Relations. Using the European migration and refugee crisis as a case study and drawing on insights from organisation studies and the sociology of the professions, the article introduces a novel theoretical framework that foregrounds improvisation by first responders and the ex-post stabilisation of their spontaneous policy solutions at headquarters. In addition to reconstructing and illustrating the mechanisms that link frontline action to changed policies, the article identifies theoretical conditions shaping the likelihood and direction of informal policy change from the ground up. By highlighting bottom-up dynamics in crises, it not only advances theoretical debates on crisis politics, but also proposes a new research agenda for analysing the transformative role of field-level practices in global politics.
