What if Trump threatens to blow up the Imam Reza Mosque?

Trump has said that if there are any attacks in response to his killing of the Iranian General, he will attack 52 Iranian sites, including site of cultural value to Iran.

From any other President, you would assume it is empty rhetoric. It is against international law to target cultural and religious sites. Even Hitler’s Generals refused to destroy such sites in France, despite Hitler telling them to do so.

So what if Trump went all the way and announced he will destroy the Imam Reza Mosque (the most holy site in Iran). Would that dissuade Iran from counter attacks?

Or would it inflame the entire Shia Islam world, and lead to a huge increase in attacks around the world?

Would any Western allies stand by Trump if he made such a threat?

Would Trump face international criminal action under UNSC 2347 which states unlawful attacks against sites dedicated to religion may constitute a war crime and the perpetrators of such attacks must be brought to justice?

We may find out soon.