Like many politicians before him, Muhammadu Buhari, Nigeria’s new president, is finding that promises made during a campaign are easy to announce, but more difficult to keep. A former army major-general who briefly seized power in Africa’s most populous state in the 1980s, Mr Buhari swept to power in April promising not only to tackle Boko Haram, the Islamist group that has wreaked havoc and bloodshed in Nigeria, but to defeat it.
