Feb. 4 (UPI) -- "Battle-hardened" Islamic State militants could retake key territory in Syria after U.S. troops leave the war-torn country, a report from the Department of Defense's inspector general said Monday.
The watchdog warned the withdrawal could lift counterterrorism pressure off the militant group -- also identified as ISIS, ISIL and Daesh -- and lead to a resurgence. The inspector general based its report on information provided by the Department of Defense.
"While U.S.-backed Syrian forces have continued the fight to retake the remaining ISIS strongholds in Syria, ISIS remains a potent force of battle-hardened and well-disciplined fighters that 'could likely resurge in Syria' absent continued counterterrorism pressure," the report said, quoting the department. "According to the DoD, ISIS is still able to coordinate offensives and counter-offensives, as well as operate as a decentralized insurgency."
Not all military officials and lawmakers agreed with Trump's assessment, and a day later, former Secretary of Defense James Mattis resigned citing a difference in vision on international policy. On Thursday, the Senate passed a resolution rebuking Trump's decision to withdraw thousands of troops from Syria and Afghanistan, calling the Islamic State a "global threat."
The inspector general report said that any opportunistic attacks on U.S. personnel amid the withdrawal would be heralded as a "victory" in Islamic State media.
"ISIS is regenerating key functions and capabilities more quickly in Iraq than in Syria, but absent sustained [counterterrorism] pressure, ISIS could likely resurge in Syria within six to 12 months and regain limited territory," the report said.
The U.S. coalition formally announced the liberation of the Islamic State's de facto capital in Syria -- Raqqa -- in October 2017. Syria has been embroiled in a civil war since 2011, with U.S. forces backing Syrian Democratic Forces in its fight against the Islamic State and forces loyal to President Bashar al-Assad.