As US troops sail to Middle East, how likely is Trump to order boots on the ground?

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, but when marines are in position next week, Trump could order an assault to either provide leverage to reopen the Strait of Hormuz or to degrade Iran’s ability to keep the waterway closed by force. 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. And an assault to take Kharg Island would mark a rare contested amphibious landing by US troops potentially under drone, rocket and artillery fire. US troops would take more than a day to sail into position near the island, giving Iran time to mine the area surrounding the island as well.If US troops were able to take the island, it remains unclear how long they would be forced to hold the territory, potentially under fire, before the US could compel Iran to reopen the Strait of Hormuz or agree to a ceasefire. Separately, the US could also intensify its bombardment of the island. The US has already hit 90 targets on Kharg Island, the chair of the joint chiefs of staff, Gen Dan Caine, said last week. “Just one simple word, and the pipes will be gone,” Trump said earlier this month, while considering an attack on the island.There are other targets – especially islands – in the Strait of Hormuz that could also appeal to the Trump administration and aid the immediate goal of reopening the waterway to commercial traffic. Qeshm Island, the largest in the Persian Gulf, is a storage site for Iranian attack craft, drones, sea mines and other materiel used to disrupt shipping. But at nearly 560 sq miles, the island may be too large for the US to occupy with its available troops.Deviation of routes of ships in Strait of Hormuz since start of the warAnother island that could be targeted is Larak, which is a hub for Iranian weapons used to maintain the choke point over shipping in the strait. The US news website Axios reported that administration officials are considering attacks on Larak, as well as the contested island of Abu Musa.But the troops Trump has sent to the region could be leveraged for other missions. The US is still searching for the 440kg of highly enriched uranium (HEU) that disappeared after the US strikes against Iran last June. Rubio has said of the uranium that “people are going to have to go and get it”, and the US is reportedly weighing up options to send in special forces backed by larger deployments of airborne troops or marines to search for and recover the material in Iran.But that mission would take weeks, cover multiple military sites and be fraught with danger for American troops – especially given Iran’s decades-long experience with asymmetric warfare and the likelihood of US casualties as a result.“I think there’s a huge concern in the Trump administration, and rightly so, about US casualties,” Max Boot, a foreign policy analyst, historian and columnist, told the Council on Foreign Relations thinktank. “And that makes it very unlikely that we’re going to have any large-scale use of US ground forces. And the Iranians aren’t stupid, they know that.”For now, Trump has delayed his main threat, the destruction of Iran’s power plants in what would be a brutal attack on Iran’s critical infrastructure, until 6 April as negotiations continue. But given the dangers surrounding a potential US ground incursion into Iran, the most likely escalation for the Trump administration would be to fulfil its threats to degrade life in Iran using the tools it has employed since the beginning of the war.