If you are referring to the office of Secretary-General, Slick will never serve in that capacity.
While it is not contained in the UN Charter, there has been an unspoken agreement since the UN's founding in 1945 that a citizen of one of the five permanent members of the Security Council (USA, UK, Russia, China, France) cannot hold the Secretary-General's office.
Slick is outta luck...
Especially “unspoken agreements” do not deter klintoons.
Where there is a will, there is a way.
It all depends on the meaning of “unspoken” and “agreements”.