The town of Nasir sits on the Sobat River in Upper Nile State, 26 kilometres from the Ethiopian border. It is a Nuer town - homes, markets, grazing land, a small airstrip - and it has been a place of repeated violence for more than a decade. On 3 March 2025, around four in the afternoon, a Nuer White Army member was killed by soldiers of the South Sudan People's Defence Forces. Within days, the army garrison had fallen, a United Nations helicopter had been fired on, and the 2018 peace agreement that had ended the country's civil war was being described, across every news wire, as near collapse.
The R-ARCSS peace agreement had been signed in 2018. By 2024, cracks were showing. Clashes in February of that year between White Army members and SSPDF soldiers over a dispute about fishing nets left several dead. A year later in February 2025, four SSPDF soldiers were killed in another confrontation, and at least ten civilians were injured when the army shelled in response. The White Army - a loose federation of Nuer community defence militias rather than any organised force - had protested the SSPDF presence, demanding that Necessary Unified Forces, the integrated national army the peace deal had promised, replace the partisan soldiers. The government said no NUF were available. Instead, it deployed Shilluk Agwelek fighters and Padang Dinka militia - ethnic groups the local Nuer regarded as hostile. Their barges came under fire on 22 February. Nine days later, the town erupted.
The fighting on 3 and 4 March unfolded in stages. White Army fighters first secured parts of Nasir and briefly occupied the Wec Yar Adiu barracks three kilometres west of town before pulling back for ammunition. They returned on 4 March and took the barracks for good. On 7 March, two helicopters of the United Nations Mission in South Sudan arrived to evacuate the trapped SSPDF troops. An exchange of fire killed a UN helicopter operator, twenty-seven SSPDF soldiers, and the garrison commander Major General Majur Dak. The remaining soldiers fled overland toward Ulang County. The fallen garrison's military equipment - mortar units, five hundred and fifty-seven AK-47 rifles, seven armoured personnel carriers, worth fifty-eight point seven million US dollars - passed to the White Army or was destroyed.
Uganda deployed special forces to Juba on 9 March. Muhoozi Kainerugaba, Uganda's Chief of Defence Forces, posted on X that his country recognised only one President of South Sudan, Salva Kiir, and that any move against Kiir would be a declaration of war against Uganda. Then the airstrikes began. On the night of 16 March the SSPDF bombed the area around the Nasir airstrip, killing twenty-one residents. Information Minister Michael Makuei Lueth ordered civilians to leave the military zone. At 3:30 the following morning, additional strikes hit the town, including the market. The bombing spread across Longechuk County, where Mathiang village was struck on 16 March; along the road between Akobo and Walgak on 18 March; and at Kuich in Ulang County on 21 March, killing one person and wounding twelve. Civilians who could fled. Many could not.
SSPDF soldiers surrounded the Juba home of First Vice President Riek Machar, the longtime Nuer leader and head of the SPLA-IO. On 4 March, General Gabriel Duop Lam, the SPLM-IO chief of staff, was arrested. Near midnight on 5 March, Petroleum Minister Puot Kang Chol was detained. On 6 March, Peacebuilding Minister Stephen Par Kuol was arrested in his office; he was released the next morning. On 11 September 2025, Machar - with seven co-defendants - was charged with murder, treason, and crimes against humanity. The government alleged he had ordered the Nasir attack. Machar denies it. A report by the Small Arms Survey, based on interviews with White Army members themselves, concluded that Machar and the SPLA-IO leadership were not responsible - that the government's central argument in the prosecution is unfounded. The trial began 22 September 2025 and, as of early 2026, continues.
On 20 April, with local leaders mediating, the White Army executed what the SSPDF spokesman called a tactical withdrawal. The army reoccupied Nasir without further fighting; the following day, the Chief of Defence Forces, Paul Nang Majok, visited to congratulate the troops. The German and Norwegian embassies in Juba, closed during the worst of the crisis, reopened on 9 June. What had happened in Nasir did not simply return to quiet. An estimated fifty thousand people had been displaced by the fighting and the airstrikes. The United Nations warned that South Sudan was on the brink. Machar's trial continues to carry existential stakes - the potential unravelling of a peace agreement negotiated at the cost of nearly four hundred thousand lives during the civil war itself.
Nasir sits on the Sobat River at approximately 8.61 degrees N, 33.04 degrees E in Upper Nile State, South Sudan, 26 km from the Ethiopian border. The Nasir airstrip served as the focal point of SSPDF operations during the 2025 clashes. From altitude the area is distinguishable by the broad meanders of the Sobat flowing west toward its confluence with the White Nile at Malakal. The region remains politically volatile; the airspace has seen military activity. Juba International (ICAO HSSJ) is the principal hub to the south. Treat as sensitive airspace subject to restrictions.