Michael Abramowitz: “Obama’s test comes in Sudan, which on Jan. 9 is supposed to hold a referendum on whether the country’s southern region will secede from the north. If the south votes for independence – as it is expected to do after decades of marginalization and a north-south civil war – deadly violence could easily erupt. The government in Khartoum has proved willing to brutalize its citizens (in the Darfur region and elsewhere) to remain in power and achieve its aims, and secession would bring to the fore unresolved tensions over Sudan’s oil wealth and where to draw the new borders.”