With the US-Iran ceasefire about to expire, could Trump put boots on the ground?

Abbas Araghchi, the Iranian foreign minister, who led two rounds of negotiations for Iran with the US before they were torpedoed by military action, was aggressively defiant when NBC asked him whether Iran feared a US ground invasion.

“No, we are waiting for them, because we are confident that we can confront them, and that would be a big disaster for them,” he said.

Ashkan Hashemipour, an Iran analyst at the University of Oxford, said of Araghchi’s remarks: “I don’t think it’s just rhetorical. It’s because Iran, right now, seems to be doing pretty well in a war that’s essentially fought in the skies and in the sea. If it’s fought on the ground, he knows that they’ll be even stronger.”

Fuelling Iranian confidence is the fact that the Islamic republic has seen – and fought off – a previous ground invasion. The 1980-88 war with Iraq was the proving ground for the current generation of Iranian military leaders.

Triggered when Saddam Hussein ordered Iraqi forces to invade Iran after the 1979 Islamic revolution, the conflict turned into a bloody war of attrition. It ended in stalemate after ideologically driven Iranian forces repelled Iraq’s better-equipped army, which had been supplied by the west as well as the Soviet Union.

The future Iranian president and supreme leader Ali Khamenei (right) speaking to members of the armed forces in Iran in October 1981, during the war with Iraq. Photograph: AFP/Getty Images

Nader Hashemi, a professor of Middle East and Islamic politics at Georgetown University, said: “That war was a foundational experience for the Iranian hardliners and conservatives. They viewed it not simply as a war between Iran and Iraq, but as a major attempt by the United States and the west to undermine the Islamic revolution.

“There are clear lines and connections that the Islamic republic draws from that experience to this current war. From their perspective, what’s happening now proves them absolutely correct. The greatest power in the world, the United States, and its biggest ally in the Middle East are trying to topple the Islamic republic, and now they want to invade and occupy it.”

Militarily and technologically outmatched by the US, Iran’s Islamic Revolutionary Guard Corps (IRGC) would be likely to depend on asymmetric tactics that would lean heavily on guerrilla warfare in the event of a US land invasion.

To give maximum flexibility, the IRGC has been divided into 31 provincial units roughly in line with the country’s 31 provinces, thereby overriding the need for a centralised command that could be eliminated or disrupted by US or Israeli strikes.

A missile is launched during the ‘Great Prophet 17’ joint exercise in south-west Iran in December 2021. Photograph: Wana News Agency/Reuters

Saeid Golkar, a politics professor at the University of Tennessee at Chattanooga, said the plan was devised after the US-led invasion of Iraq in 2003.

“The idea is to try and break Iran into a mosaic, with each mosaic defending itself,” said Golkar, an expert on the IRGC and the Basij, Iran’s volunteer militia force.

A vital role would also be played by Iran’s larger – if politically less powerful – conventional armed forces, known as the Artesh.

Under changes introduced in 2009, the Artesh was broken down into rapid action units based on 12 regional headquarters across the country – again with the purpose of freeing local commanders from central command.

The Artesh’s main role, said Hashemipour, would be to compel US forces to fight two wars – “one conventional, one unconventional” – simultaneously.

The IRGC-led unconventional war is believed to rest in part on support from the Basij, a youth volunteer force that became renowned for “human wave” attacks on Iraqi forces in the 1980-88 war, driven by a fervent revolutionary desire to attain Shia “martyrdom”.

An Iranian military boat patrols as a warship enters Iranian waters before a joint naval drill of Iran, Russia and China in the Indian Ocean. Photograph: AP

The key Basij unit would be the Imam Hussein infantry battalion, named after the grandson of the prophet Muhammad, who died at the battle of Karbala in 680.

But Golkar played down the militia’s military significance, describing it as an “instrument of domestic repression” and doubting many members’ willingness to fight, citing the decline of religious devoutness in Iran and widespread unhappiness with the regime.

With Trump’s focus on reopening the strait of Hormuz, boots on the ground could – at least initially – fall short of an incursion on to the mainland, and be limited instead to occupying one or more of several islands in the Gulf off Iran’s southern coast. But such deployments would leave US troops vulnerable to missile and drone attacks.

The Iranian regime is also likely to respond by pressuring its proxy Houthi allies in Yemen to close the Bab al-Mandab shipping lane between the Red Sea and Indian Ocean, which would cause global energy prices to rocket.

Houthi forces boarding the cargo ship Galaxy Leader in November 2023. Photograph: AP

Vaez said: “The reality is there is no military solution to reopen the strait, because even in a scenario that [Trump] occupies the entire southern shore of Iran and all the Gulf islands that Iran has, Iran will still be able to fire drones from much farther inland to disrupt traffic on the strait.”

That could pave the way for the denouement of a land war that Iran has spent 47 years preparing for after decades of shadow conflict with Washington, waged mostly through proxies in locations such as Iraq and Afghanistan.

The same guerrilla warfare tactics used in these countries, including roadside bombs made from improvised explosive devices – an approach perfected in Iraq by the former IRGC Quds force commander Qassem Suleimani – is likely to greet any US invasion force.

But Golkar notes one vital difference: the absence of a meddling outside power. “In Iraq and Afghanistan, it was Iran and the IRGC that was in the middle of these two countries, trying to create a quagmire for the Americans,” he said.

“Because there are no external countries that could support an insurgency in Iran, we will not see the same scenario as in Iraq.”

That could leave the outcome hinging on the attitudes of a disaffected Iranian population and US willingness to absorb casualties.

Vaez said: “Any kind of ground invasion would probably entail significant casualties on the US side, which is something that the Iranians actually would like to see.” He added that Trump may already have forfeited public support from regime opponents by threatening to erase Iran’s civilisation and change its borders.

“We can’t generalise the public sentiment, but it is important to take into account at what point in this conflict a ground invasion could happen. It is after President Trump has threatened to take Iran back to the stone ages.

“[Iranian] public opinion is turning against this war and putting boots on the ground is more likely to benefit the regime than to benefit its opponents because regime change could not be done with [only] several thousand US special forces and ground troops.

“If there are American boots on Iranian soil, the IRGC would would consider them sitting ducks, and would definitely try to significantly bump up the casualty numbers, because they also know that the dual [scenario] of high energy prices and high casualties would bring down Trump’s presidency.”