Following the Arab Spring uprisings , and withdrawal of the bulk of US troops from Iraq , the threat of Islamic State/ISIL/ISIS emerged , amid the deteriorating Syrian Civil War . The extremist Sunni Islamist group was battling government forces in Syria and Iraq , with the objective of establishing of an Islamic caliphate across the region . Domestic terrorist attacks by ISIS supporters occurred in Australia in 2014 , with knife and gun attacks in Melbourne and Sydney against police and civilians . In October 2014 , the Federal cabinet approved the decision to launch air strikes in Iraq in response to concerns over ISIL militant groups . Abbott announced that the Australian mission was to " disrupt and degrade " Islamic State " at home and abroad "
knife
2014 Endeavour Hills stabbings
Abbott Government