'Extraordinary' that Trump threatens 'massive' war crimes, former US Iran envoy says

US President Donald Trump has escalated his threats, saying “a whole civilization will die tonight” if Iran fails to meet this morning's deadline.

The President wants Iran to agree to a deal - which includes reopening of the Strait of Hormuz.

So, will the president follow through on his latest threat - and what are the implications of scaling up the military assault?