"It was much harder. It has not been easy, and the struggle is still ongoing," she told Reuters in her office in Abuja, the capital, exhausted by a night negotiating with oil unions. "You make progress, then you get courage to make more ... Fighting corruption is something we need to keep working at."
Okonjo-Iweala has started to tame government expenditure and make limited reforms, but her room for maneuver is limited by her restricted access to state revenue, 80 percent of which comes from oil. She has also found herself again fixing problems she tackled during her first term that ended six years ago, only for these achievements to have been undone in the meantime.
Okonjo-Iweala, who missed out on the World Bank presidency earlier this year, may yet decide to take another high-profile international job. She is tipped as a possible next World Trade Organization head, although she has so far shown no interest.
Should she decide to leave Abuja, her biggest challenge will be ensuring any reforms she makes can't be undone.
Nigeria's dysfunction is hugely profitable for some. Its moribund power grid allows importers of generators and diesel to make immense sums; dilapidated refineries leave Africa's top oil producer dependent on imported petrol that has made billionaires of a handful of tycoons thanks to a corrupt fuel-subsidy scheme. Ports are clogged with goods held up by bribe-seeking officials.
Some of the elites which profit from these inefficiencies are blocking attempts at structural reforms, including Okonjo-Iweala's, such as curbs on state spending and the removal of the fuel subsidy, raising doubts about how much they can achieve.