Yeah that has less to do with diplomacy more to do with how Iran's conducted itself ever since the Islamic Revolution. More so since except the mullahs who call the shots there everyone else from the parliament to government are just figureheads what to speak of diplomats.
Nobody likes the mullahs & it's not just the US or Europe or the Gulf Shekhdoms, it's countries like India, Russia, China etc. Beyond calls for war to stop & some cursory condemnation, there's been nothing there will be nothing.
Basically don't be like this clueless lot

running their agenda masquerading as foreign policy all the while accusing the government of doing so.
View: https://youtu.be/m-PEhlmoplI?si=RHG-J1uBujHn7UYZ
Except Katju, everyone was.... well you can see for yourself & decide.