The world’s youngest country fought for decades to govern itself. Now it’s on the cusp of another civil war

South Sudan soldiers patrol the street in Juba, South Sudan, on February 13, 2025.Brian Inganga

CNN— 

A peace deal ending a conflict that killed tens of thousands in South Sudan is in danger of collapsing, raising fears that the world’s youngest nation — and one of its poorest — could swiftly lapse back into war.

South Sudan split from the rest of Sudan in 2011 after decades of pro-independence unrest but has struggled to keep the peace in its territory, which is divided along ethnic lines.

It plunged into a civil war in 2013 and then again three years later, until the violence was stopped by a fragile ceasefire agreement in 2018.

What’s the current crisis about?

The nation is governed by a coalition government, led by President Salva Kiir and five vice presidents, who include Kiir’s rival Riek Machar, the leader of the SPLM/A-IO party.

South Sudan's president Salva Kiir, left, and vice-president Riek Machar, right, shake hands after meetings to discuss outstanding issues to the peace deal on October 20, 2019.Sam Mednick

Machar was arrested this week, prompting the SPLM/A-IO to issue a statement Thursday saying his detention “effectively brings the (peace) agreement (between him and Kiir) to a collapse.”

“The prospect for peace and stability in South Sudan has now been put into serious jeopardy,” it added.

CNN has asked the SPLM/A-IO what it thinks could happen next but has not heard back.

Machar’s arrest followed the sacking and arrest of other prominent officials from the SPLM/A-IO, as well as the arrival of troops from neighboring Uganda at Kiir’s invitation to help South Sudan’s military fight a local militia. The SPLM/A-IO condemned what it called “military aggression against civilians” by the Ugandan forces.

Machar also condemned Uganda’s military intervention in a letter to the United Nations’ secretary-general on March 23, saying it violated the terms of the peace deal.

South Sudan has never held a national election. Its current government is the result of a power-sharing agreement struck in 2018 between Kiir and Machar. The deal ended a five-year-civil war, which killed an estimated 400,000 people.

South Sudan is polarized between the majority Dinka tribe, which Kiir hails from, and Machar’s Nuer ethnic group, the second-largest in the country.

Clashes this month in the town of Nasir between government forces and a Nuer militia known as the White Army have shaken the nation’s fragile peace. Dozens have been killed in the clashes, local media reported.

South Sudan security forces sit with the coffin of General David Majur Dak, the commander of the South Sudan People’s Defense Forces, who was killed when a United Nations helicopter trying to evacuate people from Nasir came under attack by the White Army militia.Samir Bol/Reuters

On Friday, authorities confirmed Machar’s arrest, accusing him of encouraging the militia to overrun a military base in Nasir and attack a UN helicopter. The White Army, for its part, denies ties with Machar or his party.

Information minister Michael Makuei said in a statement sent to CNN that since the beginning of March Machar had been “agitating” a rebellion against the government “with the aim of disrupting peace so that elections are not held and South Sudan goes back to war.”

He cited “intelligence and security reports.”

Makuei added that Machar and “his anti-peace colleagues of the SPLM/A-IO” – which he said preached hate and tribalism – “will be investigated and brought to book accordingly.”

The SPLM/A-IO has not commented on these allegations