Perhaps a counter threat might make them back off, one along the lines of a warning to all civilians in Tehran and the other cities to flee immediately their leaders close the straights as the cities will be promptly annihilated.
Lets just clarify it..........you are advocating mass murder based on military and political decisions by some leaders.
Assume then you don't have a problem with Russia and China carrying out similar when US / Nato park its military on another countrys borders...