The departure of US troops from Iraq in 2011 ended the period of occupation that had begun with the U.S.-led invasion in March 2003. The time since U.S. withdrawal has been marked by a renewed Iraqi insurgency and by a spillover of the Syrian civil war into Iraq. By 2013, the insurgency escalated into a renewed war, the central government of Iraq being opposed by ISIL and various factions, primarily radical Sunni forces during the early phase of the conflict. The war ended in 2017 with an Iraqi government and allied victory, however ISIL continues a low-intensity insurgency in remote parts of the country.