During his second presidential term, Obasanjo's priority in international affairs was no longer to restore Nigeria's reputation or create new continental institutions, but rather to strengthen those institutions, to use them and his own international standing to resolve conflict and foster democracy and development, and to free Nigeria from its burden of foreign debt. At the peak of his influence in 2005, he was chairman of the African Union (from July 2004 to January 2006), the NEPAD Heads of State and Government Committee, the Group of 25, and the Commonwealth – an array of posts that irritated other African leaders. His extraordinary energy enabled him to conduct all these duties conscientiously – he was an unusually active chairman of the African Union and the Commonwealth – while also presiding imperiously over his own turbulent country and personally conducting much of its foreign policy, the Foreign Minister for most of the period being a career diplomat.

Obasanjo was no longer yoked to President Mbeki: the divide between them that had opened during 2003 over Zimbabwe widened markedly during the next two years. Nor, once debt relief was secured in 2005, was Nigeria still a supplicant to the Western industrial powers. Rather, it was an aspiring regional power in its own right, dominating the Gulf of Guinea, whose oil reserves made it the one region of tropical Africa that was of more than marginal importance to the rest of the world. Looking westwards, Nigeria was an increasingly important ally of the United States, supplying some 12% of American oil imports, supporting a large Muslim population, and acting as a key peacekeeper throughout sub-Saharan Africa.