Ethnic violence in South Sudan has a long history among South Sudan's varied ethnic groups. South Sudan has 64 tribes with the largest being the Dinkas, who constitute about 35% of the population and predominate in government. The second largest are the Nuers. Conflict is often aggravated among nomadic groups over the issue of cattle and grazing land and is part of the wider Sudanese nomadic conflicts.
In 2010, Dennis Blair, then United States Director of National Intelligence, issued a warning that "over the next five years,...a new mass killing or genocide is most likely to occur in southern Sudan." In April 2017, Priti Patel, the Secretary of the United Kingdom's Department for International Development, declared the violence in South Sudan as genocide.
Those from the Murle and the Lou Nuer are largely nomadic cattle herders. Cattle are used as food and are used as a store of wealth. It takes 20 cows to buy a bride if a young man hopes to marry, which encourages cattle raiding. Violence between the two groups go back generations, exacerbated by tensions over land and water. The attacks often target an entire village, burning them in their round thatched huts. Militias frequently abduct children during cattle raids, who are then raised as their own. This is seen as a method, notably among the Murle, to increase the numbers of the small minority group. In past generations, attacks used machetes and sticks. However, after decades of civil war, the region is awash with guns, and young men are now armed with high-powered weapons. In 2017, local organizations said that more than 5,000 people were killed since 2011 in cattle raids in South Sudan.
The governing party, the Sudan People's Liberation Movement (SPLM), and the army, the Sudan People's Liberation Army (SPLA), have been accused of being dominated by the Dinka. Many refer to the dominance of Dinkas as the "Dinkocracy". A Dinka lobbying group known as the "Jieng Council of Elders" is often accused of being behind hardline SPLM policies. While the army used to attract men from across tribes, during the South Sudanese Civil War, the SPLA had largely become a militia of soldiers from the Dinka stronghold of Bahr el Ghazal, home region of President Kiir and the Chief of Staff, and the army was often referred to within the country as "the Dinka army". Much of the worst atrocities committed are blamed on a group known as "Mathiang Anyoor" (Brown caterpillar) or "Dot Ke Beny" (Rescue the President), a militia of Dinkas formed to protect Kiir and Paul Malong Awan, while the SPLA claim that it is just another battalion.