The 2014 Eastern Syria offensive was an offensive launched by the Islamic State of Iraq and the Levant (ISIL or IS) against government-held military installations in eastern Syria during the Syrian Civil War, after expelling the Syrian rebels from the region. The offensive is considered to be the largest military attack against the Syrian government launched by ISIL since its establishment. It is also considered to be a reaction to Syrian Army military operations against ISIL positions in eastern Syria.