After launching the most ambitious reforms in his country's history Ethiopia's Prime Minister, Abiy Ahmed, is under threat. The murder of his army chief of staff amid an alleged coup attempt in the Amhara region has highlighted the vulnerability of the reform process. The BBC's Africa Editor, Fergal Keane, analyses the challenge facing the continent's youngest leader.
Just a few weeks ago, Abiy Ahmed was riding high and feted across Africa as a reformer.
He had released political prisoners, appointed women to more than half of his cabinet posts, persuaded a noted dissident to head the country's election board, and staged an historic rapprochement with neighbouring Eritrea after decades of conflict.
When I met him in December last year he was brimming with confidence, even telling me that the world should look to Ethiopia "to see how people can live together in peace."