The U.S. Congressional Research Service published a thoughtful report on 5 October 2012 titled "Sudan and South Sudan: Current Issues for Congress and U.S. Policy." The author is Lauren Ploch Blanchard.
The report examines the shared interests and outstanding disputes between the Sudans after separation, and gives an overview of political, economic, and humanitarian conditions in the two countries, with a focus on possible implications for U.S. policy and congressional engagement.
Click here to read the report.