The Brief provides the context for understanding current tensions in the Nuba Mountains region of South Kordofan, where Nuba and Arab groups are becoming increasing militarized. It finds that: * The area is highly militarized with both parties to the conflict actively violating the Comprehensive Peace Agreement (CPA), including by recruiting members of armed groups. * Khartoum's paramilitary Popular Defence Forces (PDF) are being reorganized in the region on a sharper ethnic basis than in the past. * Arabs returning to animal migration routes closed by the war are being armed, often through the PDF, with a corresponding mobilization by some settled tribes. * UNMIS has done little to calm tensions, in contrast to the active efforts of the much smaller number of unarmed ceasefire monitors, the Joint Military Commission (JMC), which were present from 2002­05. * There is considerable resentment among Nuba about how the CPA protocol on South Kordofan dealt with the region, providing little in the way of enforceable autonomy and deferring the most important questions on land ownership and access and security arrangements. The Brief concludes that discontent is turning to anger, and many now view war in the Nuba Mountains as inevitable.