World War II had a major political, economic and social impact on the Middle East. In Syria, the overthrow of the pro-Vichy French government and subsequent Allied occupation in 1941 disrupted the already fragile political order under the French colonial regime, eventually paving the way for independence. Recent scholarship has further highlighted the role of Allied-imposed supply regimes, shedding light on their profound influence on both wartime dynamics and post-war transformations in the region. Nevertheless, this period remains largely understudied in the historiography on the modern Middle East. This paper addresses this gap by examining the impact of wartime supply regimes on tribal populations in the Syrian Jazira region. Specifically, it focuses on the so-called Office des Céréales Panifiables (O.C.P.), which was introduced in 1942 by the British and French colonial powers, with limited Syrian and Lebanese participation, to establish a state monopoly on the Syrian grain market. The Jazira’s population, as the main producers of grain in the region, was significantly affected by policies that mandated the seasonal delivery of pre-determined grain quotas to the O.C.P. Using archival material from the French and British colonial administrations, supplemented by material from Syrian newspaper, this paper analyses two interrelated sets of conflicts. First, it examines the tension between the rigid categorisation of administratively defined tribes, which formed the basis of the O.C.P.’s quota system, and the fluid social structures within the tribal population. This tension contributed to widespread resistance to O.C.P. policies and ultimately led to the failure of the supply system. Second, the paper examines the implications for tribal shaykhs and mukhtar-s, who, as representatives of the tribal collective, assumed primary responsibility for ensuring the “correct” and timely delivery of grain, and were consequently held accountable for the failure of the system. These dynamics, the paper argues, led to a crisis of tribal categories and politics of tribal representation that had underpinned the larger political order in rural Syria throughout the colonial period. Against this backdrop, tribal politics thus emerged as a central issue of negotiation and conflict between various tribal and state actors vying for political influence at the dawn of Syrian independence. In that vein, the paper seeks to contribute to recent scholarship that has considered tribes not simply as historical actors, but as contested categories that were continuously reconstituted within a broader social and political context.