Following the Houla massacre of 25 May 2012 , in which 108 people were summarily executed , and the subsequent FSA ultimatum to the Syrian Ba'athist government , the ceasefire practically collapsed , as the FSA began nationwide offensives against government troops . The peace plan practically collapsed by early June and the UN mission was withdrawn from Syria . Annan resigned in frustration on 2 August 2012
Houla massacre
Houla massacre
2012–13 escalation of the Syrian Civil War