they're voluntary. there is no mechanism in this accord that would actually enforce any of these rules on any of the participating countries, unlike the previous kyoto protocol. there was no real reason for trump to withdraw from this treaty. world leaders will know this. the only reason was a gesture. it was a way to say, we are not going to be bound, even by rules that were voluntarily imposed on us, by ourselves. this is turning their backs -- trump is turning his back not just on these other world leaders and the environment but, as i mentioned before, on this entire international global order. it goes way beyond just questions of the environment to questions of diplomacy and how the united states will handle itself moving forward under president trump's direction. craig? >> matt bradley for us this morning in london. thank you. supreme decision. the trump administration appealing to the nation's highest court to allow it to start enforcing its block travel ban. our man at the justice department, pete williams, with