This book examines different domestic and international factors that lead to support for secessions. It questions why South Sudan’s secession was successfully supported by Western great powers while Somaliland and Western Sahara were not supported. It argues that support for secessions and international recognition have more to do with the great powers’ own interests, particularly, the U.S., rather than the fulfillment of the criteria of international law.The analysis examines six competing arguments (hypotheses) such as: history of conflict; agreed framework and commitment of local population; compatible norms and internationalized ethnic politics; status of the mother state in the eyes of the international community; economic benefits, and security and stability interests in the case of South Sudan. A comparison of these hypotheses with the cases of Somaliland and Western Sahara shows unique case of support for South Sudan statehood.