In A Long Walk to Water, what is Uncle's plan once he drops Salva off at the refugee camp in Ethiopia?

Salva is amazed and gladdened in equal measure by the sudden re-appearance of his Uncle Jewiir after so many years. He now feels so much safer to have this experienced soldier with him on the long, hard journey to the Itang refugee camp in Ethiopia.
Salva naturally assumes that his uncle will stay with him when they get to Ethiopia, but unfortunately for Salva, Jewiir has other ideas. Once he's dropped off Salva at the refugee camp, he plans to return to Sudan, where he will carry on fighting for the South Sudanese rebel army as before. Jewiir is a loyal and faithful soldier to the cause, and there was no way he was ever going to abandon his comrades in their hour of need. Salva is understandably saddened to hear of Jewiir's plans, but hopes that his uncle will be able to locate his family and send them word where he is.