South Sudan is in crisis. Since winning independence from Sudan in 2011 after decades of bloodshed, the country has faced a troubled existence. Despite having large oil reserves that could fuel a strong economy, South Sudan remains one of the world’s least developed countries. Government institutions are dysfunctional. Political and ethnic rivalries between President Salva Kiir and Vice President Riek Machar caused the government to effectively collapse in late 2013, plunging the country into a civil war marked by ethnically targeted attacks.

This conflict has led to a severe humanitarian crisis in South Sudan. Nearly four million South Sudanese, out of a population of about eleven million, have been driven from their homes, disrupting agricultural production and local markets. As a result, food shortages and health needs have grown severe. Over 383,000 people [PDF] have died since the beginning of the conflict.

Although a UN peacekeeping mission has been present in South Sudan since 2011, this crisis has also led other countries, including the United States, to consider launching their own humanitarian interventions to establish or maintain peace and ensure access to humanitarian aid. Such interventions would be guided by the responsibility to protect (R2P) doctrine, adopted by all member states of the United Nations in 2005 after they failed to prevent a number of genocides. According to this doctrine, countries have a responsibility to intervene in other countries in cases of crimes against humanity or genocide. However, this norm is not legally binding and its application in past cases has been controversial. Nevertheless, the underlying principles of R2P could serve as a rationale for the United States to take action in South Sudan.