Hezbollah fighters joined with Syrian President Bashar al-Assad’s forces on Sunday to take back large swaths of Qusayr, a border city in Homs Province controlled by rebel fighters. The Syrian military pounded the city with air and artillery strikes, leaving 52 dead and injuring hundreds. Anti-government activists estimated regime loyalists took back roughly 60 percent of the city. It was a significant win for Assad, who believes the area is key to regaining control over rebel-held territories. Hezbollah’s role in the conflict has escalated recently, raising fears that the war may soon spread beyond Syria’s borders.