From a rocky outcrop overlooking a limestone quarry in the desolate valley below, a fighter from Hezbollah surveys what just days before had been territory controlled by militants linked to al-Qaeda. “There were snipers behind every rock,” recalls the young man with a wispy moustache. The operation to drive the jihadists from their mountain lair on Lebanon’s north-east border with Syria began on July 21st. It took only a week for Hezbollah to defeat its militant rivals, adding yet another victory to its growing list of military achievements since war broke out in Syria six years ago.

Along with Russian air power and Iranian military aid, Hezbollah’s ground units have kept the regime of Bashar al-Assad, Syria’s blood-soaked president, in power. The cost has been high. About 2,000 of the group’s fighters, out of a total of perhaps 15,000 (excluding reservists), have died on Syria’s front lines. But the conflict has also transformed Hezbollah, a Lebanese militia-cum-political party. Hardened by the fighting and flush with arms from Iran, it now more closely resembles a regular—and quite effective—army. That worries Israel, its traditional adversary.

Read the full article at the Economist.