Rwanda's Paul Kagame has won a second term as president. Having ruled the war-torn country since 1994, and claiming — quite rightfully — to have ushered in a period of peace after civil war and genocide, he had been expected to win another election. But beneath the calm that prevails in Rwanda is the fear that Mr. Kagame is another despot in waiting, who will stay in power after his new term expires — despite constitutional prohibitions.

If Mr. Kagame wishes to be remembered as the man who truly restored order, prosperity and justice to Rwanda, he must work within the legal system and respect the limits on the powers of the president.

Mr. Kagame grew up as a refugee in Uganda, having fled Rwanda as a small child. He rose through the ranks of the Rwanda Patriotic Front (RPF), a Tutsi-led military force that was fighting the Hutu-majority government in Rwanda. In April 1994, a plane carrying the presidents of Rwanda and Burundi crashed on its approach to the airport of Kigali, the capital of Rwanda. The plane was brought down by a missile: Who fired it is disputed to this day.