Nuba Mountains, Sudan – Mohamed Radi, a Rapid Support Forces fighter, lies on a bed in a tent in the courtyard of the Mother of Mercy Hospital in Sudan’s Nuba Mountains in late April.

The 23-year-old is in his second week of recovery after a Sudanese Armed Forces (SAF) drone struck his unit in the town of Khor al-Delib, costing him his right foot.

Next to him is another RSF fighter, his leg mangled by a landmine.

The reason these fighters can rest and recover here, about 170km (100 miles) southeast of el-Obeid, is that the Sudan People’s Liberation Movement-North has allowed them in, in a development that embodies the rapidly shifting nature of Sudan’s alliances.

SPLM-N reached an alliance with the RSF in February, choosing sides in a war between the paramilitary and SAF that has racked Sudan since April 2023.

As Sudan’s civil war approaches three years, Al Jazeera gained rare access to the Nuba Mountains to report on life there under a new military alliance.

Access was allowed on the condition that a translator from a local NGO and a representative of the government media office come along, which may have made some people wary of speaking.