Five men from a small French town that supplied around 20 jihadists to the war in Syria, most of whom never returned, went on trial Thursday accused of a terrorist conspiracy. Lunel, a town of 26,000 people outside the coastal Mediterranean city of Montpellier, became a symbol of the jihadist fervor sweeping parts of France when a group of friends slipped out of the country to Syria in 2013 and 2014. At least eight members of the group are believed to have been killed in Syria, with another seven missing in the war-torn country. The outsize number of recruits from...