In the latest cycle of threats and concessions that have marked US President Donald Trump’s approach to the war that he and his Israeli counterpart started against Iran, the mercurial president said on Thursday he would destroy any undersized boat attempting to lay mines in the blocked Strait of Hormuz.

His focus on diminutive vessels followed his oft-repeated messaging that Iran’s larger naval vessels are no more as he renews his effort to muscle Tehran’s frustratingly resilient regime to concede defeat.

“I have ordered the United States Navy to shoot and kill any boat, small boats though they may be … that is putting mines in the waters of the Strait of Hormuz”, Trump wrote on social media, adding that Iran has no navy since “ALL 159 of them” are at the bottom of the sea.

Trump added that the US military is intensifying mine-clearing operations in the strategic waterway. This comes after his administration retired its four Avenger-class minesweeper ships, the last specialised such vessels in the region. These are being replaced with a new class of vessels that stay out of the conflict area and send drones in to do the work, a concept the Pentagon reportedly said has not yet been “battle-tested”.

“There is to be no hesitation. Additionally, our mine ‘sweepers’ are clearing the Strait right now,” Trump declared. “I am hereby ordering that activity to continue, but at a tripled up level!”

But analysts say global anxiety is as much about the threat of danger felt by global cargo carriers and maritime insurers than actual attacks as a cornered Iran has effectively deployed fear and insecurity to hold hostage the global economy.