This chapter provides a micro-level analysis of why and how the reformist insurgency-society contract formed for three years between the Sudanese Liberation Movement/Army (SLM/A) and the non-Arab Darfur society in Sudan (2003–2005) through the Grievance-Driven Pathway using the Comprehensive Social Contract (CSC) Framework. The government’s Arabization agenda and tendency to centralize its development resources led to the marginalization of many of Darfur’s non-Arab population. Government triggers slowly mobilized the Fur, Masalit, and Zaghawa general populations to slowly come together through predominantly an out-grouping process. These same triggers mobilized first actors from these three tribes toward unorganized opposition and then armed opposition, establishing the SLM/A. The government’s predation through military forces and pro-state proxy militias led many from Darfur’s non-Arab tribes to eventually bond with the SLM/A. The SLM/A drew on the region’s pre-war social bases and was perceived as legitimate due to its shared values and mandates for self-defense, to agitate through political violence to get the government’s attention, and to reform the Sudan-society contract. Despite the successful government’s counterinsurgency campaign, the unmitigated and compounding grievances have sustained the movement, contributing to the Juba Peace Agreement that revised the Sudan-society contract in 2019.