A few days before he was elected Egypt’s president in May, Abdel Fattah al-Sisi discreetly visited tribesmen living along the border with Libya. Tribal leaders there say Sisi, former head of the army, urged them to help Egypt confront what could be a security nightmare for the biggest Arab nation: Islamist militants operating just over the frontier in Libya.

“Sisi came to us and asked us to stand behind the security forces and army to help them to control the border because what is happening in Libya poses a grave danger to Egypt,” said Mohamed al-Raghi, a tribal chief.

Wearing a flowing white robe and a traditional black cap outside a mosque in the border town of Salloum, Raghi said he and other tribal leaders had assured Sisi they would help him. […]