Nigeria is an important regional power that is still struggling to emerge as a stable democracy in west Africa. The country is still dealing with two regions of domestic instability, with an ongoing insurgency in the oil producing Delta region, and violent clashes in the north. President Yar' Adua has not been seen in nearly two months while being treated for an undisclosed medical condition in Saudi Arabia. Who's on deck if the opposition gets its way and he is declared unfit? Vice President Goodluck Jonathan.