- Salva Kiir fired Riek Machar in 2011, which touched off the country's brutal civil war
- Machar's reappointment was part of a peace deal the two men signed
- Thousands of people have died in the conflict
South Sudan, the world's newest country, has been embroiled in one of the world's most brutal -- and under-reported -- conflicts since December 2013.
President Salva Kiir ousted vice president Riek Machar in 2013, accusing soldiers loyal to Machar of attempting to stage a coup.
That sparked the current round of violence and inflamed ethnic tensions in the country. Kiir is a member of the country's majority Dinka population, while Machar is Nuer, the country's second-largest ethnic group.
Since the conflict started, thousands of people have been killed -- some say
as many as 50,000. More than 2 million people have been displaced, according to the United Nations
. Almost 3 million people -- nearly a quarter of the country's population -- are in "urgent need of aid."
A report from the African Union
revealed that forced cannibalism, gang rapes and death by burning had all occurred during the conflict.
Machar and Kiir signed a peace agreement in August, though clashes have continued sporadically in the country. The deal called for a transitional national unity government to be put in place by early February.