The President may enter into treaties, the advise and consent occurs after the fact of the negotiation, not before!
The proper place for the Cotton letter was, as others have pointed out in this ongoing debate, the Wall Street Journal or another such conservative publication: not as a direct communication to one of the parties of that negotiation, that can be characterized as the American antagonist. The political intent of the Cotton missive was not just to embarrass, but to hold the President up to international ridicule,with the intent to engage in sedition of a presidential prerogative, pure and simple. The Republican Party is in the thrall of a practice of a destructive political nihilism, and Cotton and his Neo-Con mentors, like William Kristol, have overstepped the bounds of the idea and practice of the ‘loyal opposition’, into the territory of the friend/enemy distinction that animated the political thought of Carl Schmitt!
StephenKMackSD