SUMMARY
South Sudan became independent from Sudan on 9 July 2011, with the Government of South Sudan assuming authority over the newly established state. The government was dominated by the Sudan People's Liberation Movement/Army (SPLM/A), the former rebel movement that had fought against the Government of Sudan during the Second Sudanese Civil War between 1983 and 2005. The war began after the Sudanese government introduced Islamic law and attempted to centralized political control, prompting the SPLM/A under John Garang to launch an armed struggle advocating greater autonomy and political reform for southern Sudan. The conflict ended with signing of the Comprehensive Peace Agreement (CPA) in 2005, which granted Southern Sudan autonomy and established a transitional Government of National Unity before the independence referendum in 2011. Following the independence, SPLM/A leader Salva Kiir became South Sudan’s first president, while the SPLM/A transformed from a rebel movement into the country’s dominant political and military authority.
At independence, South Sudan faced significant political, economic, and security challenges. Relations with Sudan remained tense, particularly over unresolved disputes concerning border demarcation, oil revenues, and contested territories such as Abyei. Both governments also accused each other of supporting insurgent movements across the border, with Khartoum allegedly backing armed groups in South Sudan while Juba was accused of supporting Sudanese rebel groups, particularly in Blue Nile and South Kordofan.
Internally, the new state remained deeply fragmented after decades of conflict. During the North-South war, the Sudanese government had frequently employed divide-and-rule tactics by supporting rival southern militias against the SPLM/A, contributing to long-tern political, military, and ethnic divisions within South Sudanese society. Although the SPLM/A emerged as the dominant force after independence, internal rivalries within the government persisted, particularly among military commanders and political elites.
Tensions intensified between President Salva Kiir and Vice President Riek Machar over political leadership, governance, and control of the ruling SPLM/A. In July 2013, Kiir dismissed Machar and dissolved the cabinet, further deepening divisions within the government and armed forces.
On 15 December 2013, fighting erupted in the capital, Juba, between rival factions of the SPLA aligned with Kiir and Machar, triggering a nationwide civil war. Shortly afterward, Machar announced the formation of the Sudan People’s Liberation Movement/Army-in-Opposition (SPLM/A-IO), which emerged as the main armed opposition movement against the Government of South Sudan. The conflict rapidly spread across Jonglei, Unity, and Upper Nile states as military units defected to the SPLM/A-IO. The war was characterized by large-scale atrocities, ethnic violence, and widespread displacement, with the conflict increasingly taking on ethnic dimensions between communities associated with President Kiir, predominantly Dinka, and those aligned with Machar, largely Nuer.
A series of regional and international mediation efforts led to several ceasefire agreements and eventually to the signing of the Revitalized Agreement on the Resolution of the Conflict in South Sudan (R-ARCSS) in 2018. The agreement established a transitional power-sharing arrangement and led to Machar’s reinstatement as First Vice President in 2020. Despite the agreement, tensions between the government and SPLM/A-IO persisted, particularly over security sector reforms, governance, and the integration of rival armed forces, contributing to continued instability and periodic clashes in several parts of the country.
The conflict over government between the Government of South Sudan and SPLM/A-IO resumed in 2025 for the first time since Riek Machar becoming the First Vice President within the transitional government. The deterioration accelerated in early March following large-scale attacks in Nasir country in Upper Nile state, led by the White Army, an independent Nuer self-defense militia that has at times been loosely aligned with SPLM/A-IO but operates autonomously. Following the attacks, President Kiir arrested Machar along with several senior SPLM/A-IO political and military officials, accusing them of backing the rebellion. SPLM/A-IO rejected the accusations, denied responsibility for the Nasir violence, and declared the peace agreement effectively collapsed. Throughout the remainder of 2025, fighting between government forces and SPLM/A-IO intensified across Upper Nile, Jonglei, and parts of Equatoria.
The Government of South Sudan has been involved in the interstate, intrastate and one-sided categories of UCDP organised violence.
