East Africa / Horn of Africa / Sudan Cluster·Republic of South Sudan

South Sudan Civil War (2013–Present)

Also known as: South Sudan’s civil war; the Kiir-Machar conflict; the Dinka-Nuer war; the R-ARCSS crisis

EscalatingCivil War; Political Crisis; Ethnic Conflict; Failed Peace ProcessEast Africa / Horn of Africa / Sudan ClusterDecember 2013–present; primary armed phase 2013–2018; R-ARCSS transitional period 2018–2025 (now collapsed); resumed conflict 2025–present

Kiir, Machar, and the Fragile Peace Process

Background

South Sudan’s civil war is among the most catastrophic political failures in the post-Cold War era of African statehood. A country that gained independence in July 2011 with overwhelming international goodwill, substantial oil revenue, and genuine popular celebration descended within less than three years into a brutal civil war that killed an estimated 400,000 people, displaced millions, produced famine, and destroyed the institutional foundations of the new state. As of mid-2026, the conflict has entered a new and potentially more dangerous phase: the collapse of the 2018 Revitalised Agreement on the Resolution of the Conflict in South Sudan (R-ARCSS), the imprisonment of First Vice President Riek Machar on treason charges, and fighting across eight of South Sudan’s ten states that the International Crisis Group has described as the country having ‘returned to war’. The roots of the conflict lie in the political dynamics of the Sudan People’s Liberation Movement (SPLM) — the liberation movement that governed South Sudan after independence. The SPLM’s wartime culture was characterised by personalised authority, ethnic patronage, and an internal governance model built on military hierarchy rather than democratic accountability. At independence, the SPLM had to transform from a liberation army into a civilian state — but it lacked the institutional depth, democratic culture, or political will to do so. The oil revenues that began flowing in 2005 under the Comprehensive Peace Agreement (CPA) — $2.1 billion annually between 2006 and 2009 — were captured by the patronage networks of SPLM leaders rather than invested in building state institutions, creating a neopatrimonial political economy in which access to the president’s favour was the only reliable mechanism of economic advancement. President Salva Kiir Mayardit and former Vice President Riek Machar had been rivals within the SPLM since the early years of the liberation war: the Bor Massacre of 1991, in which Machar’s Nuer forces killed thousands of Dinka civilians, had poisoned their relationship irreparably. The two men’s post-independence rivalry was overlaid on this ethnic history, mapping Dinka (Kiir’s base) against Nuer (Machar’s base) in ways that transformed a political conflict into an ethnic war. On 15 December 2013, fighting broke out in Juba between soldiers of the presidential guard (Tiger Battalion) following what the government claimed was a coup attempt by Machar-aligned forces. The context was a political confrontation at an SPLM National Liberation Council meeting; Kiir had accused Machar and 10 others of plotting against him, and Machar had denied it. Whether the December 15 fighting began as a genuine coup attempt, an accidental confrontation, or a government-provoked incident remains disputed. What is not disputed is that within days, it had escalated into systematic ethnic massacres: Dinka soldiers in Juba killed hundreds of Nuer civilians; Nuer White Army militia massacred Dinka civilians in Bor. The war spread across the country along broadly ethnic lines.

Main Actors

President Salva Kiir Mayardit (SPLM): President of South Sudan since independence (2011). Ethnic Dinka from Warrap state. Led the government and the South Sudan People’s Defence Forces (SSPDF) throughout the conflict. Accused by opposition and analysts of systematically using the peace process to consolidate personal power rather than build national institutions. In March 2025, placed First VP Machar under house arrest and charged him with treason, effectively dismantling the R-ARCSS.
First Vice President Riek Machar Teny (SPLM-IO): Former Vice President of Sudan under the CPA; SPLM leader who became South Sudan’s first First Vice President at independence. Led the SPLA-IO (Sudan People’s Liberation Army-In Opposition) from 2013. Returned as First VP under the 2018 R-ARCSS. Placed under house arrest March 2025; SPLM-IO declared R-ARCSS defunct. On trial for treason and crimes against humanity as of mid-2026. A Nuer, his ethnic identity was central to the conflict’s ethnic mobilisation.
South Sudan People’s Defence Forces (SSPDF): Government armed forces. Kiir-aligned. Dominated by Dinka-recruited units. Conducted major offensive operations in Jonglei, Upper Nile, and Unity states in 2025–2026. Accused of airstrikes on civilian areas and of using starvation as a tactic by blocking humanitarian access to opposition-controlled territories.
Sudan People’s Liberation Army-In Opposition (SPLA-IO): Opposition armed forces aligned with Machar. Nuer-dominated, but includes other ethnic groups. Has been fighting government forces across multiple states since 2013. Following Machar’s arrest in March 2025, SPLM-IO declared the R-ARCSS defunct and resumed armed operations. Fighting in Jonglei, Upper Nile, and Central Equatoria as of mid-2026.
White Army (Nuer community militia): Nuer ethnic community militia with autonomous command, loosely allied with Machar but not under SPLA-IO control. Conducted the February 2025 attack on the Nasir army base that precipitated Machar’s arrest. Has played a major role in fighting in Jonglei and Upper Nile in 2025–2026.
Uganda People’s Defence Forces (UPDF): Has repeatedly intervened in South Sudan in support of Kiir, including providing air support in the 2013–2014 and 2016 phases and in 2025–2026 operations in Upper Nile. Uganda’s President Museveni has been Kiir’s most consistent regional ally.
United Nations Mission in South Sudan (UNMISS) -------------------: UN peacekeeping mission that has been present since 2011. Provides protection of civilian (POC) sites and monitors human rights. Mandate renewed by UNSC; faced significant resource constraints from UN financial crisis as of 2025–2026. Has documented systematic violations including airstrikes on civilian areas and conflict-related sexual violence. ----------------------------------------------------

Drivers

Neopatrimonial state and SPLM political dysfunction: South Sudan’s post-independence political system reproduced the liberation movement’s patronage networks, creating a winner-take-all dynamic in which political marginalisation translated immediately into physical insecurity. The failure to build inclusive institutions meant that the Kiir-Machar rivalry expressed itself as armed conflict because there were no credible institutional mechanisms for managing it otherwise.
Dinka-Nuer ethnic polarisation: The SPLM’s internal split mapped onto South Sudan’s two largest ethnic groups, both of which mobilised their youth militias — the Dinka Mathiang Anyoor and the Nuer White Army — for ethnic violence. The 1991 Bor Massacre provided a historical frame in which mutual grievances were activated with devastating speed.
Oil revenue capture and economic collapse: South Sudan’s economy is almost entirely dependent on oil revenues (over 95% of government income), which flowed through Juba’s patronage networks rather than into state institutions or services. The January 2012 oil shutdown crisis (when South Sudan and Sudan could not agree on oil transit fees) demonstrated the economy’s fragility. Oil revenues fund the war rather than reconstruction.
Implementation failure of peace agreements: Both the 2015 ARCSS and the 2018 R-ARCSS were implemented selectively by Kiir: security sector reform (unifying the SSPDF and SPLA-IO into a single national army) was never implemented; elections were repeatedly postponed; opposition officials were systematically replaced by presidential loyalists. The agreements froze rather than resolved the conflict.
Succession politics and regime fragility: The International Crisis Group’s 2026 analysis identified Kiir’s ailing health and intense jockeying among SPLM elite figures for succession as a driver of the 2025 political crisis. Kiir’s concentration of power within a shrinking inner circle, multiple reshuffles of senior officials, and the appointment of family members to positions all signal a regime managing succession by eliminating rivals rather than building institutional succession mechanisms.

Timeline

9 July 2011
South Sudan declares independence. Salva Kiir becomes president; Riek Machar First Vice President. Oil revenues fund construction of state institutions, but patronage networks capture most resources.
January 2012
South Sudan shuts down oil production in dispute with Sudan over pipeline transit fees. Production suspended for 15 months; severe economic shock to both countries.
23 July 2013
Machar and 10 senior SPLM leaders publicly criticise Kiir’s government for authoritarianism and call for party reform. Kiir dismisses the entire cabinet, including Machar as First VP.
15 December 2013
Fighting breaks out in Juba between presidential guard units following an SPLM National Liberation Council meeting. Government claims Machar attempted a coup; Machar denies it and flees. Ethnic massacres of Nuer civilians in Juba begin immediately. SPLA-IO formed under Machar’s leadership.
December 2013– January 2014
Civil war spreads across South Sudan: Nuer White Army massacres Dinka civilians in Jonglei (including Bor); government forces massacre Nuer civilians in Juba and elsewhere. Thousands killed in the first weeks.
August 2015
Agreement on the Resolution of the Conflict in South Sudan (ARCSS) signed in Addis Ababa under IGAD pressure. Provides for power-sharing and security integration. Machar returns as First VP in April 2016.
July 2016
Renewed fighting between SSPDF and SPLA-IO forces in Juba. Machar flees; Kiir replaces him with Taban Deng Gai, splitting the SPLA-IO. ARCSS collapses.
2016–2018
Fighting spreads across Equatoria region, previously relatively peaceful. Large-scale displacement; famine declared in Unity State (first famine in Africa in over a decade) in 2017. Atrocities documented on all sides.
September 2018
R-ARCSS (Revitalised Agreement on the Resolution of the Conflict in South Sudan) signed in Addis Ababa. Provides for a new power-sharing arrangement with Machar restored as one of five vice presidents.
February 2020
Transitional Government of National Unity (TGoNU) formed. Kiir as president; Machar as First VP. Transitional period begins; elections scheduled for December 2022, then postponed to December 2024, then December 2026.
2020–2024
Repeated implementation failures: security sector reform stalled; unified national army not formed; permanent constitution not drafted; electoral process not launched; opposition officials progressively replaced by Kiir loyalists. Localised violence continues across multiple states.
December 2024
Kiir dismisses long-serving intelligence chief and begins a series of reshuffles that narrow his inner circle. Tension with Machar’s SPLM-IO faction intensifies.
February 2025
White Army militia overruns an SSPDF base in Nasir, Upper Nile, killing 20+ soldiers and displacing thousands of civilians. Government blames Machar — a charge analysts dispute.
March 2025
Kiir places Machar under house arrest and charges him with treason. SPLM-IO declares the R-ARCSS defunct. Opposition insurgency intensifies. Uganda’s UPDF deployed to support SSPDF in Upper Nile.
April–June 202
5 Fighting spreads to Jonglei, Upper Nile, Central Equatoria, and other states. SSPDF airstrikes documented by MSF in multiple locations. UN Commission on Human Rights in South Sudan warns of catastrophic consequences.
September 2025
Trial of Machar begins in Juba for treason and crimes against humanity. SPLM-IO denounces the trial as politically motivated. ICG describes South Sudan as sliding back into civil war.
January 2026
UNMISS Human Rights Division reports 295 conflict-related violence incidents July–September 2025: 519 killed, 396 injured, 159 abducted, 79 subjected to conflict-related sexual violence. Fighting in 8 of 10 states at a scale not seen since 2018.
February–June 2026
Fighting continues in Jonglei and Upper Nile. Opposition forces make territorial gains. SSPDF conducts airstrikes. ICG Watch List Spring 2026 identifies South Sudan as one of the world’s most critical conflict escalation risks. Elections scheduled for December 2026 face extreme security obstacles.

Humanitarian Impact

South Sudan’s cumulative humanitarian toll is among the most severe of any conflict in sub-Saharan Africa over the past decade. The primary civil war phase (2013–2018) killed an estimated 400,000 people and displaced nearly half the population: by 2018, approximately 4 million people were internally displaced and 2+ million had become refugees in Uganda, Sudan, Kenya, Ethiopia, and the DRC. Famine was declared in Unity State in 2017 — the first famine declaration in Africa since Somalia in 2011. Sexual violence against civilians was systematically used as a weapon of war by both SSPDF and SPLA-IO forces, extensively documented by the UN Commission on Human Rights. The 2018 R-ARCSS and the 2020 formation of the TGoNU produced an initial reduction in violence but not a genuine humanitarian recovery: as of 2024, approximately 10 million South Sudanese — over two-thirds of the population — required humanitarian assistance. Successive climate shocks (flooding, drought) compounded conflict-related displacement; the collapse of oil prices and the loss of oil revenue due to the Sudan Civil War’s impact on pipeline infrastructure deepened economic crisis. The 2025–2026 escalation has produced a new humanitarian emergency. The UN-coordinated South Sudan Humanitarian Needs and Response Plan describes needs at their worst level since 2011. SSPDF airstrikes on civilian areas have been documented by MSF. The government has been accused by US officials and aid organisations of deliberately blocking humanitarian access to opposition-controlled populations as a tactic of collective punishment. Funding for the humanitarian response has dropped to its lowest level since independence, including the severe cuts to USAID-funded programmes from early 2025 onward.

Peace Efforts

Agreement on the Resolution of the Conflict in South Sudan / ARCSS (August 2015): IGAD-mediated agreement providing for a Transitional Government of National Unity. Partly implemented after Machar’s return in April 2016; collapsed in July 2016 after renewed Juba fighting. The agreement’s security integration provisions were its fatal weakness: neither side wanted genuine integration of their forces into a unified national army.
R-ARCSS (September 2018): Revitalised Agreement on the Resolution of the Conflict, providing for a new power-sharing government with Machar as one of five vice presidents. The TGoNU was formed in February 2020. Implementation consistently undermined by Kiir’s unilateral dismissals of opposition officials, non-implementation of security sector reform, and multiple extensions of the transitional period. Declared defunct by SPLM-IO following Machar’s March 2025 arrest.
Community of Sant’Egidio mediation (January 2020): A peace declaration between the South Sudanese government and the SSOMA (South Sudan Opposition Movements Alliance), a coalition of armed groups outside R-ARCSS (including Thomas Cirillo’s NAS and Paul Malong’s SS-UF). Partially implemented; some SSOMA factions integrated into SSPDF, others remain outside.
IGAD and regional diplomatic engagement (2025–2026): IGAD, the AU, and individual regional states have appealed for de-escalation following the March 2025 Machar arrest and the resumption of large-scale fighting. Uganda’s Museveni mediated directly. No ceasefire has been achieved; fighting in Jonglei and Upper Nile escalated through May–June 2026.
Elections (December 2026): South Sudan’s first ever general elections were repeatedly postponed and are currently scheduled for December 2026. Security conditions across 8 of 10 states, the non-completion of a permanent constitution, and the effective collapse of the TGoNU make the prospect of credible elections by December 2026 extremely uncertain.

Current Situation

As of mid-2026, South Sudan has effectively returned to civil war. The International Crisis Group’s January 2026 briefing concluded without ambiguity: ‘It is now indisputable: South Sudan has returned to war.’ Fighting between SSPDF and SPLA-IO forces is occurring in eight of ten states at a scale not seen since the 2018 R-ARCSS. Jonglei and Upper Nile are the primary theatres, with significant fighting also in Central Equatoria and other areas. SSPDF airstrikes on civilian areas are a defining feature of the government’s military strategy, according to MSF, which documented the pattern from May 2025 onward. Riek Machar’s ongoing trial in Juba — on charges of treason and crimes against humanity, related to the February 2025 Nasir incident — is itself a source of conflict risk. The SPLM-IO has made Machar’s release a precondition for any ceasefire discussions; the government insists the trial is a legal proceeding that must run its course. Kiir has continued to reshuffle his own party and government, narrowing his inner circle in ways that multiple analysts associate with succession dynamics rather than governance imperatives. South Sudan’s fiscal crisis has worsened in parallel with the security collapse. A UK court ruling in May 2026 blocked South Sudan from entering new oil-backed pre-payment deals until it repays outstanding debts, cutting off one of the government’s primary liquidity mechanisms. The economy, already severely constrained by the Sudan Civil War’s disruption to oil pipeline infrastructure (South Sudan’s oil exports transit through Sudan), faces acute deterioration.

Outlook

Short-Term (0–12 months) Critical. Fighting across eight states is intensifying. The December 2026 elections face near-insurmountable obstacles: no ceasefire, no completed constitution, no credible electoral framework, and security conditions incompatible with free or fair voting. A humanitarian catastrophe in Jonglei and Upper Nile is unfolding. The risk of large-scale ethnic massacres — as warned by the Guardian in March 2025 and the Global R2P in April 2026 — is assessed as elevated. Medium-Term (1–3 years) Without a political process that releases Machar, restores meaningful power-sharing, or produces a genuine transition framework, the civil war will continue. Uganda’s military involvement creates the risk of regional escalation. The Sudan Civil War’s impact on oil export infrastructure threatens to eliminate South Sudan’s primary revenue source. A full-scale return to the 2013–2018 intensity of conflict — with mass displacement, famine, and systematic atrocities — cannot be excluded. Long-Term (3+ years) South Sudan’s long-term viability as a state depends on whether, after the current conflict phase, a genuine power-sharing framework can be constructed that addresses the structural drivers of the conflict: ethnic polarisation, neopatrimonial resource capture, military impunity, and the absence of inclusive institutions. Multiple rounds of peace agreements have failed because they provided political accommodation without institutional transformation. A durable settlement will require security sector integration, transitional justice for conflict-era atrocities, and economic diversification beyond oil dependence.

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Version: 1.0 (Pilot)
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