So, EVERY mayor in the country has the right to decide whether or not they will recognize established diplomatic protocol and establish his own foreign policy?
Yea, I think so. As long as we’re a republic rather under a central authority, the Federal Government is limited on what it can compel municipalities to do. But like you said, there’s an element of disrespect for the office if they don’t cooperate so refusals like Rudy’s should be rarely if ever employed.