Donald Trump’s threats to carry out mass bombing of civilian infrastructure in Iran present US military officers with a dilemma: disobey orders or help commit war crimes.

It is an urgent matter for the US chain of command. In an expletive-laden threat, Trump set a Tuesday 8pm Washington time deadline for the Iranian government to open the strait of Hormuz or face “Power Plant Day, and Bridge Day, all wrapped up in one”.

There is little debate among legal experts that such an attack on the life-supporting infrastructure for 93 million Iranians would constitute a war crime.

“Such rhetorical statements – if followed through – would amount to the most serious war crimes – and thus the president’s statements place service members in a profoundly challenging situation,” two former judge advocate general (JAG) officers, Margaret Donovan and Rachel VanLandingham wrote on the website Just Security on Monday.

“As former uniformed military lawyers who advised targeting operations, we know the president’s words run counter to decades of legal training of military personnel and risk placing our warfighters on a path of no return.”