US-Iran Stalemate: Trump's Remaining Military Options

US President Donald Trump has declared on his Truth Social platform that he will not attack Iran before the November 3 midterm elections. But it was also Trump who told a Republican conference in September that the conflict "will end right after the elections," while US forces have continued to build up in the region in recent weeks.

Meanwhile, Iranian attacks on shipping in the Strait of Hormuz have risen to their highest level since the war began. An Iranian official told Reuters that Tehran has begun using different attack tactics against vessels it regards as violating restrictions it has imposed.

With control of the Strait of Hormuz still the focal point of the US-Iran conflict, the question is what military options Washington has left, and what each would cost. Al Jazeera spoke with military analysts to shed light on the issue.

Where the US-Iran war stands now

It is deadlocked.

The US and Israel first struck Iran on February 28, opening the door to Iranian retaliation against US military assets and other infrastructure in Gulf states and Jordan over the following months.

Iran also closed the Strait of Hormuz, the shipping lane that carried at least 20 percent of global crude oil and liquefied natural gas supplies before the war, upending world energy markets. The global crude benchmark rose from about $72 a barrel a day before the fighting began to nearly $120 earlier this year. By Thursday it was trading at about $104 a barrel.

A June ceasefire collapsed over the dispute about control of the strait. Washington maintains a naval blockade of Iran's southern ports, while Iran keeps attacking ships that try to pass through. Indirect talks via Pakistan and Qatar continue, along with exchanges of proposals, but Trump rejected Iran's latest offer to reopen the strait last month.

The US possesses "immense military capability Iran cannot match," yet has not achieved the result Washington wanted, according to Afzal Ashraf, a visiting fellow in international relations and security at Loughborough University in the UK and a former senior Royal Air Force officer who served in Iraq.

US forces in the Middle East

The US has at least three carrier strike groups in the Gulf or en route.

The USS Theodore Roosevelt carrier strike group, carrying about 7,000 sailors and 2,000 Marines, is heading to the Middle East to join carriers already there. The US also keeps large amounts of military hardware and roughly 50,000 troops at various bases across Middle Eastern countries.

Trump's military options

Keep squeezing Iran

The US naval blockade of Iranian ports and the escorting of commercial ships through the Strait of Hormuz is the status quo Washington can sustain. It is the most viable option, according to Patrick Bury, a senior lecturer at the University of Bath and a former NATO research analyst.

Before the war, the Strait of Hormuz typically saw about 125 large commercial vessels a day, carrying an average of 17.1 million barrels of oil. That traffic collapsed when the strait was closed in March.

In recent weeks, thanks to US Navy escorts, the flow of oil from the Gulf through Hormuz -- excluding Iranian oil -- recovered to more than 81 percent of pre-war levels in September, according to shipping tracker Kpler. But that recovery has reversed as Iran steps up attacks on shipping in the strait. According to Kpler, only 2.9 million barrels of oil moved through the route on October 11, the lowest level of the month.

Washington is trying to maintain patrols and surveillance in the southwestern part of the strait, "enough to give shipping some protection to get out," Bury said. Drones are increasingly taking on the heavy lifting of providing intelligence and carrying out strikes, cheaper than keeping aircraft aloft on long missions. "It's partially effective," he said, adding that high oil prices and crew bonuses mean "people are willing to accept a certain amount of risk."

But Iran has now changed tactics. Britain's United Kingdom Maritime Trade Operations recorded 15 attacks on ships between October 6 and 14. Iran appears to have prepared carefully, Bury said, pointing to "the asymmetry of cost." Thanks to its geography, Iran still has "an easier starting point," he said.

Resume air strikes and missile attacks

This is another option. Trump has said it could be "feasible" to intensify bombing after the elections, but gave no details.

If the situation escalates, Bury said he would expect "more air strikes on a fairly limited scale" targeting Iranian coastal targets and deeper inland.

According to Ashraf, a new campaign could "achieve a lot less" than the strikes earlier this year, because Iran has adapted. "They have fewer weapons, but they can hide better," he said.

The cost would also be high for the US, which has depleted much of its stock of expensive defensive missiles. Every relatively cheap Iranian drone or missile can force the US to fire "an interceptor costing a million dollars or more," he said, and "the US is running down its missiles for its own defense."

Moreover, the US has fired more than 1,000 Tomahawk cruise missiles at Iran over the course of the war. According to estimates by the Center for Strategic and International Studies, fully restoring pre-war stockpiles could take until the end of 2030.

Rebuilding stocks of key munitions to pre-war levels would take "three to four years," Bury said. "The problem is that it takes a very long time to fix, even when you turn on the money tap."

Tehran has also pledged a stronger response. Parliament speaker Mohammad Bagher Ghalibaf declared last month that the era of "proportional retaliation" was over.

According to Ashraf, new strikes could also cost Washington access to some Gulf bases. Iran's recent retaliation has targeted Jordan, Kuwait and Bahrain, while leaving some other Gulf states alone that Ashraf said may have reached understandings with Tehran to stay out of the conflict.

Would the US launch a ground campaign?

Experts say it is highly unlikely.

One potential target could be Kharg Island, 26 km off Iran's coast, which handles about 90 percent of Iran's exports. Joseph Votel, a former commander of US Central Command, has said 800 to 1,000 troops could seize the island, but they would be highly vulnerable to fire from mainland Iran, according to Reuters.

Ashraf said US forces could carry out a limited incursion, likely having to open with electronic warfare to blind Iranian defenses. But Iran would then strike the island itself. "They don't need much targeting information once they know the island has been taken by US troops," he said. "And tolerance for casualties is very low in a war that is already deeply unpopular."

He warned Iran could also hit oil and gas infrastructure across the Gulf in retaliation, and concluded that seizing Kharg Island would be "the most irrational decision among irrational decisions."

Could the US invade Iran outright?

That is also highly unlikely.

Trump has largely ruled out a ground assault, while Secretary of State Marco Rubio said in March that combat troops were not needed to achieve the administration's objectives.

"I don't think they'll do it," Bury said, adding that "honestly, I don't think they can."

Why does the timing matter?

The war is deeply unpopular with the American public, and Trump faces midterm elections in just a few weeks. About 65 percent of Americans disapprove of Trump's handling of the war, according to the Pew Research Center.

Bury said the bigger question is whether the US can rebuild its military power in a short time. "Can America regenerate its military superpower status in the next few years?" he asked, saying the task would outlast Trump's term, because "whatever successor president will have to do the same thing."

According to Ashraf, the longer the war drags on, the greater the risk of instability spreading across the region, and "military options should not be separated from the immense capacity to cause political instability."

On Sunday, Iran's top security official Mohsen Rezaei said Tehran had attacked ships in the US-backed escort corridor through the Strait of Hormuz every night for weeks. "You are smuggling," he said, "but the strait is under Iran's control."