Mattis: US should stay in Iraq after Islamic State is defeated

Defense Secretary Jim Mattis and Joint Chiefs Chairman Gen. Joseph Dunford both told Congress Wednesday that a residual force of U.S. troops should remain in Iraq after the Islamic State is defeated to prevent a resurgence of the terrorist group. That's in line with what Secretary of State Rex Tillerson said Wednesday at a meeting of the coalition to defeat the Islamic State in Washington.

Testifying before a Senate Appropriations subcommittee, Mattis said it would be a mistake to declare victory and leave, as the U.S. did in 2011.

"I don't see any reason to pull out again, and find the same lesson," he said.

Many analysts blame the Obama administration for failing to negotiate an agreement with the government of former Iraq Prime Minister Nouri al-Malaki to keep U.S. troops in an advisory role, a failure they argue led to the rise of the Islamic State.