The 13-year civil war in Syria has resurfaced with a rebel offensive on Aleppo, one of Syria's largest cities. The fighting has the potential to be game-changing if Syrian government forces are unable to hold their ground. The surge in fighting raises the prospect of another violent front opening in the Middle East. Aleppo, a center of commerce and culture, was seized by rebels in 2012 and was later retaken by government forces backed by Russian airstrikes in 2016. Israeli airstrikes in Aleppo this year have targeted Hezbollah weapons depots and Syrian forces.