U.S.-Russia tensions over Syria will not 'spiral out of control': Mattis

By Phil Stewart and Idrees AliWASHINGTON (Reuters) - Tensions between the United States and Russia will not "spiral out of control" following last week's U.S. cruise missile strikes on a Syrian air base, Defense Secretary Jim Mattis said on Tuesday, describing it as a one-off response to Syria's use of banned chemical weapons.President Donald Trump, in his biggest foreign policy decision since taking office in January, ordered the strikes after concluding that Syria waged a nerve gas attack in r