This: The banned weapons and the facility to produce them no longer exist. They cannot be used by 'either' or 'any' side to attack anyone.
Trump had to do this before we pull out of Syria because if he did it after, he would not have 'intelligence' in the field to provide the exact targeting information that was needed to keep civilian casualties to a minimum.
But John Kerry assured us before that Assad got rid of his chemical weapons.
Most US power comes not from just weapons, but having them present and ready to be used when the command is given, so that others avoid doing things that would cause said weapons to be used.
On that subject, the Truman strike group set sail to the eastern Mediterranean on Wednesday.