“Amid tentative White House efforts at diplomacy to end the war in Iran, US troops have also been arriving in the region to deliver what Donald Trump has hoped could be a knockout blow if he can’t negotiate a ceasefire with Tehran.”

“Thousands of US marines aboard navy amphibious ships from the 31st and 11th expeditionary units have been deployed to the Middle East from Asia.”

“Another 2,000-odd paratroopers from the 82nd Airborne are also being sent to the theatre – they are tasked with deploying worldwide within 18 hours of notification and execute parachute assaults, including against a 'defended airfield' to prepare for further ground operations.”

“The secretary of state, Marco Rubio, repeated on Friday that the US believes it will be able to achieve its goals without boots on the ground.”

“The lack of heavy armoured units, logistical depth and other elements needed for a protracted military conflict will limit the White House’s ability to escalate the conflict, however, potentially extending a stalemate that could be devastating to the international economy.”

“The most prominent target has been Kharg Island, a coral outcrop of less than 9 sq miles, off Iran’s coast.”

“The island is the site through which about 90% of Iran’s crude oil exports flow, making it a financial and logistical lifeline for Tehran, the loss of which could mark a significant blow to the regime.”

“Trump has suggested an attack against Kharg Island as far back as the 1980s, when he told the Guardian he would 'do a number on Kharg Island; I’d go in and take it' if Iran fired on US ships.”

“The US troops being deployed to the region are far fewer than those used in past major operations, including Iraq and Afghanistan.”

“The US has already hit 90 targets on Kharg Island, the chair of the joint chiefs of staff, Gen Dan Caine, said last week.”