Government forces lost control of Syria's second city Aleppo on Sunday for the first time since the country's civil conflict began after a lightning rebel offensive dealt a severe blow to President Bashar al-Assad. While the offensive had clearly been planned for some time, says France 24's Kethevane Gorjestani, it was timed to exploit an opportunity created by the broader geopolitical situation that has seen Assad's backers weakened or distracted by other conflicts.