Following the Houla massacre of 25 May 2012 , in which 108 people were summarily executed , and the subsequent Free Syrian Army ( FSA ) ultimatum to the Syrian Ba'athist government , the ceasefire practically collapsed , as the FSA began nationwide offensives against government troops . On 1 June 2012 , President Assad vowed to crush the anti-government uprising . On 12 June 2012 , the UN for the first time officially proclaimed Syria to be in a state of civil war . The conflict began moving into the two largest cities , Damascus and Aleppo
Houla massacre
Houla massacre
2012–13 escalation of the Syrian Civil War