The recent deployment of US forces inside Syria does not amount to an “invasion” and is legal under current authority, though a new authorization by Congress could go a long way to showing the public’s support to the anti-ISIS mission, Defense Secretary James Mattis said. “ISIS bulldozed the border in its geographic caliphate,” Mattis told the Senate Appropriations Defense Subcommittee on Wednesday. “The removed border is a reality in the terms of the war we had to deal with. We could not draw an imaginary line in the middle of the enemy.” The US has deployed troops inside Syria recently, including in the contested city of Manbij. Mattis said the deployment does not amount to an invasion of Syria, noting the US must “play the ball as it lies.” Operation Inherent Resolve kicked off in 2014 without a new Authorization on the Use of Military Force, though there have been repeated attempts by both the Obama Administration and several lawmakers to pass a new authorization. If Congress passed a new AUMF, it would “be a statement of the American people’s resolve,” Mattis said. The Pentagon has participated in several reviews of the AUMF issue, and the department believes it does have legal authority though a new AUMF would be helpful, said Gen. Joseph Dunford, Chairman of the Joint Chiefs of Staff, in the hearing.
See also: Undeclared War from the March issue of Air Force Magazine.