Intel brief: Riek Machar on trial: South Sudan’s fragile peace at risk

casper4871
Sep 22
3 min read

Date: 23/09/2025

What happened?

On 22/09/2025, a treason trial began against the Vice President of South Sudan, Riek Machar. Machar is charged with murder, treason and crimes against humanity in relation to an attack by a militia earlier this year. Alongside him, seven others are also charged, including petroleum minister Puot Kang Chol.
The trial, however, is crucial for the future of South Sudan. The latest break between Machar and the South Sudanese President Salva Kiir is not just interpersonal friction but represents an interethnic clash too, as both men belong to different ethnic groups. Kiir, the president, is a Dinka (around 35.8% of the country), while Machar belongs to the Nuer people (+-15.6%). Puot Kang Chol also belongs to the Nuer group.
Shortly after independence in 2011, South Sudan got engulfed in a devastating civil war which spanned from 2013 to 2020 and was largely the result of unresolved ethnic tensions. South Sudan is home to 60 different ethnic groups. The civil war ended in 2020 and the peace agreement encompassed a power-sharing agreement in which the most dominant ethnic groups (Dinka and Nuer) would both occupy important state positions to maintain balance. The composition between Dinka Kiir and Nuer Machar was a result of that agreement. While good in theory, the power-sharing relationship always remained fragile, partially also due to personal differences between the two most important political figures in the world’s youngest nation.
Aside from this week’s trial, tensions were already mounting for months. In March, of 2025 heavy fighting took place between the White Army, an ethnically Nuer militia, and the South Sudanese army (SSPDF). A UN helicopter was shot down and dozens were killed on both sides.
As a response to the Nasir clashes, the SSPDF increased their pressure on the White Army, with significant collateral damage. On 18/03/2025, an army airstrike killed 21 civilians in the same town where earlier clashes took place, Nasir.
Around 26/03/2025, it was reported that Vice President Riek Machar was put under house arrest, adding significantly to pre-existing tensions in the country.
On 27/03/2025, the SPLM-IO, Riek Machar’s political party, stated that his arrest cancelled the pre-existing peace deal.
Several months of the uneasy status quo followed, until renewed tensions in September. On 02/09/2025, renewed fighting in South Sudan led to 14 killed, also in the Nasir area.
On 11/09/2025, in an escalating turn of events, Riek Machar was charged with murder, treason and crimes against humanity for his alleged involvement in the fighting in Nasir earlier in March.
Slowly, the fragile power sharing in South Sudan appeared to break down. On 12/09/2025, the SLPM-IO publicly stated that the government is trying to enforce ‘one tribe rule’. Not long after, on 17/09/2025, the same party called for regime change.

Analysis

The trial of Vice President Riek Machar of South Sudan is much more than just a legal proceeding: it is a turning point in South Sudan’s post-civil war fragile political experiment. By putting Machar, the most influential Nuer political figure in the country, on trial for crimes against humanity, Kiir’s government is effectively dismantling the power-sharing structure that has held South Sudan together since 2020, designed to balance power among South Sudan’s patchwork of ethnic groups. The fact that Petroleum Minister Puot Kang Chol is also on trial signifies that it is not just about Machar - it appears to be a wider effort to sideline the Nuer in South Sudan’s political structure.

The consequences are already visible. The SPLM-IO, Riek Machar’s political party, a predominantly Nuer political party and important player in South Sudanese politics has already called for a regime change, which means that in essence, the power-sharing agreement has failed.

Looking forward, the situation in South Sudan warrants close monitoring as violence could re-escalate at a moment’s notice. If Machar is convicted, the likelihood that the situation might escalate is high, as several Nuer hardliners might see the South Sudanese state as being an opponent to Nuer interests. Backing down from the charges would mean that Kiir could be perceived as weak by giving in to the pressure. The only other viable option would be mediation by the African Union or any other mediating third-party. A complete failure of mediation would mean that South Sudan could slip back into civil war.

Conclusion

The trial of South Sudan’s Vice President Riek Machar threatens to destabilize the country at its core, as it signals not only a political struggle but also the marginalization of one of its key ethnic communities from a power-sharing framework crafted after the 2020 peace deal. With tensions already rising and the balance of representation unraveling, the outlook for the world’s youngest nation remains uncertain. Without mediation, South Sudan risks sliding back into the interethnic violence that has defined much of its history since independence in 2011.