good morning. we begin this half-hour with the latest push back from syrian president assad. in an interview sunday, assad told journalist charlie rose there was not any conclusive evidence about who is to blame for those chemical weapons attacks. >> assad suggested rebels were responsible for the attack. when asked about the remarks, secretary of state kerry answered "the evidence speaks for itself." >> lawmakers on capitol hill return today from of a five-week summer break facing a vote on whether to authorize military action in syria. the president visits the hill tomorrow to make his case face to face. the lawmakers have gotten an earful from constituents back home. abc's karen travers explains how we got to this point. >> reporter: president obama insists u.s. military action in syria will be different. >> this is not iraq. this is not afghanistan. >> reporter: the president says a limited, targeted strike will not lead the u.s. down the path into another unpopular war in