Military regimes favoring Islamic-oriented governments have dominated national politics since independence from the UK in 1956. Sudan was embroiled in two prolonged civil wars during most of the remainder of the 20th century. These conflicts were rooted in northern economic, political, and social domination of largely non-Muslim, non-Arab southern Sudanese. The first civil war ended in 1972, but broke out again in 1983. The second war and famine-related effects resulted in more than 4 million people displaced and, according to rebel estimates, more than 2 million deaths over a period of two decades. Peace talks gained momentum in 2002-04 with the signing of several accords; a final Naivasha peace treaty of January 2005 granted the southern rebels autonomy for six years, after which a referendum for independence is scheduled to be held. A separate conflict that broke out in the western region of Darfur in 2003 has resulted in tens of thousands of deaths and nearly 2 million displaced; as of late 2005, peacekeeping troops were struggling to stabilize the situation. Sudan also has faced large refugee influxes from neighboring countries, primarily Ethiopia and Chad, and armed conflict, poor transport infrastructure, and lack of government support have chronically obstructed the provision of humanitarian assistance to affected populations.