Jordan is preparing to set up a security zone in southern Syria to prevent a jihadi victory in the area, carving out the first humanitarian “buffer zone” for rebels and refugees in four years of civil war. The main aim of the operation will be to create a safe area on Jordan’s border, stretching across the southern Syrian provinces of Deraa and Suwayda, and including the city of Deraa, where the Syrian uprising began in 2011, according to people familiar with the plans.