well, history belies thatObama was building trust and he put he put a halt to the nuclear progream. Trump completely reversed that.
Except a multi-lateral agreement depends on every party fulfilling their obligations. The US withdrew so now no one owes anyone else.
Which wouldn't have happened if Hillary got elected.
https://fas.org/sgp/crs/nuke/R40094.pdf
not to mention the notion of fulfilling obligations.
and, you have no way of knowing what Hillary would or would not.