Given Nigeria's size, wealth and geopolitical importance, there is a tendency to assume that its president can speak for his continent. When Muhammadu Buhari landed in Washington this week, international media were fixated on a foul-mouthed January tirade by Donald Trump, wherein he likened African countries to a toilet.
But those expecting fireworks were left disappointed. More than 15 months after Mr Trump took office, Mr Buhari is the