A policeman in 2011 in Abyei, a dividing line between northern and southern Sudan that was the site of a long-running standoff. For decades, Sudan’s military has waged brutal conflicts in the south, east and west of the country. The two sides ultimately negotiated a peace agreement that split the country in 2011 after southerners voted in a referendum for South Sudan to become a new nation. Image Celebrations in Juba, Sudan, on the eve of independence for South Sudan in 2011. Credit... Tyler Hicks/The New York TimesWithin South Sudan, infighting in the government led to clashes in 2013 and ultimately triggered a violent feud between the two biggest ethnic groups. Nuba Mountains conflictClashes between government forces and rebel Nuba fighters in Sudan’s South Kordofan State broke out in the aftermath of South Sudan’s secession, with Nuba fighters supporting South Sudan.

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