Recent developments in Syria's civil war show an escalation of involvement from outside countries and groups, with outcomes increasingly difficult to predict. As the fractured rebel groups continue their battles against forces loyal to President Bashar Assad, the European Union recently voted to end an arms embargo, opening the possibility of new weapons shipments to the rebels. The Shia militant group Hezbollah, from neighboring Lebanon, has sent fighters and support into Syria to aid Assad's troops. Russia plans to ship several modern anti-aircraft missile systems to Syria, to deter foreign interference. Israel, meanwhile, is prepared to use force to stop the delivery of such systems, which it views as a threat. Gathered here are recent images from the ongoing conflict, now more than two years old.