Syrian rebel fighters began preparations to seize Aleppo a year ago but the operation was delayed by war in Gaza and ultimately launched last week when a ceasefire took hold in Lebanon, the head of Syria's main opposition abroad told Reuters.

Syrian and Russian jets are stepping up strikes on opposition forces in northern Syria in retaliation for the sudden offensive that has cost the regime control of the country’s second largest city, Aleppo.

Syria carried out airstrikes targeting the rebel forces that seized the country's second largest city of Aleppo in a surprise advance last week that caught the government off guard.

A historian explains why U.S. sanctions and Iran and Russia’s entanglements in other wars helped create an opening for rebel groups to overrun the Syrian Army.

Turkey will be the key player in ending the rebel push by Syrian insurgents against President Bashar al-Assad.

Syria’s devastating civil war, responsible for more than 300,000 deaths, was never officially resolved. Lightning gains by rebels opposed to President Bashar al-Assad were opportunistic, but also indicated years of patient preparations.