“What gives any president the right to make a unilateral decision of this magnitude?”
I would hazard that it comes from the part of the constitution where it says he is commander in chief of the armed forces.
Underscoring the importance of placing only qualified individuals in this powerful position.....
.....The POTUS is the CIC and must make rational strategic decisions. He is not the head litigator for specific racial groups, environmental activists, specific religions (Islam in this case), or foreign countries.
If the people vote for these qualities and ignore totally the CIC role of the POTUS, we risk a rogue President who can lead us to military stand-down and being open for easy attack. THIS is our situation today. Obama is leading us to an increasingly bare and defenseless position.