Since 1983, conflict, displacement, and insecurity have led to an ongoing complex emergency in Sudan. For 21 years, Sudan experienced Africa's longest conflict, during which fighting, famine, and disease killed more than 2 million people and displaced approximately 500,000 people to neighboring countries and 4 million others within Sudan. Humanitarian agencies began to provide emergency assistance in 1988, following famine, significant displacement, and heightened conflict between Government of Sudan (GoS)-supported forces and the southern-based Sudan People's Liberation Army.
In 2005, the former GoS and the Sudan People's Liberation Movement signed the Comprehensive Peace Agreement (CPA), forming the Government of National Unity (GNU) and officially ending more than two decades of north-south conflict. Since 2005, the U.N. estimates that more than 2.2 million people displaced during the conflict have returned to Southern Sudan and the Three Areas of Southern Kordofan State, Blue Nile State, and Abyei Area, further taxing scarce resources and weak infrastructure.
In Sudan's western region of Darfur, a conflict continues among armed opposition factions, the Sudanese Armed Forces, militias, and ethnic groups. Since 2003, the conflict has affected approximately 4.7 million people, including nearly 2.7 million internally displaced persons (IDPs). Since 2006, increased insecurity, attacks on aid workers, and bureaucratic impediments to program implementation have reduced humanitarian access to affected populations. In March 2009, the GNU expelled 13 international relief organizations and closed three national aid organizations, further restricting the provision of emergency assistance to vulnerable populations in Darfur and the Three Areas. Despite these challenges, remaining relief agencies continue to provide essential humanitarian assistance to populations in need.