From the Document: "Iraq's government declared military victory against the Islamic State organization (IS, also ISIS/ISIL) in December 2017, but insurgent attacks by remaining IS fighters continue to threaten Iraqis as they shift their attention toward recovery and the country's political future. Approximately 5,000 U.S. troops remain in Iraq at the invitation of the Iraqi government and provide advisory and training support to Iraqi security forces. However, some Iraqi political groups are calling for U.S. and other foreign troops to depart, and they may seek to force Iraqi government action on this question during 2019."
CRS Report for Congress, R45633
Congressional Research Service: https://crsreports.congress.gov/