Iran‘s use of a swarm of small, fast boats to seize two container ships near the Strait of Hormuz could undermine suggestions US forces have disabled its naval threat and reveals the challenges facing reopening one of the world’s most important oil export routes.

US President Donald Trump on Monday acknowledged that while Iran’s conventional navy had been largely destroyed, its “fast-attack ships” had not been considered much of a threat.

He said any such vessels coming near a US blockade set up outside the strait would be “immediately ELIMINATED” using the “same system of kill” deployed in the Caribbean and Pacific where US air strikes have hit suspected drug boats and killed at least 110 people.

Those boats were not attacking large, unarmed commercial ships, however, nor nearly as heavily armed, with Iran‘s Revolutionary Guards packing heavy machineguns, rocket launchers and, in some cases, anti-ship missiles.

Speedboat attacks now form part of a “layered system of threats,” alongside “shore-based missiles, drones, mines, and electronic interference to create uncertainty and slow decision-making,” Greek maritime security company Diaplous told Reuters.

Iran was estimated to have hundreds, if not thousands, of these boats before the war, often hidden in coastal tunnels, naval bases, or among civilian vessels, according to maritime security specialists.

Some 100 or more may have been destroyed since the Iran war began on Feb. 28, said Corey Ranslem, chief executive of maritime security group Dryad Global.

CHANGE IN TACTICS

Before this week, Iran had relied on missile and drone strikes to hit shipping traffic around the strait, a route which normally handles 20% of the world’s daily oil and liquefied natural gas supply.

Those attacks had stopped with the April 8 ceasefire.

The seizure of the two container ships by Iran followed Washington imposing a blockade on Iran‘s trade by sea and the start of it intercepting Iran-linked oil tankers and other ships.

“The civilian shipping industry is not equipped to prevent Iranian armed forces from seizing vessels,” said Daniel Mueller, a senior analyst at British maritime security company Ambrey.

Typically, about a dozen boats are used in a seizure operation, he added.

Iran‘s fast boats now serve as the “backbone” of Iran’s naval strategy, able to deploy rapidly as part of its “asymmetrical war against the enemy,” a senior Iranian security official told Reuters.

“Because of their very high speeds, these boats can successfully carry out hit-and-run attacks without being detected,” the official said, speaking on condition of anonymity.

FAST BOAT LIMITATIONS

Including this week’s seizures, Iran has used small, fast boats at least seven times going back to 2019, Ambrey’s Mueller said.

High winds and swells in the waters off Iran during summer make it hard to conduct such operations, said one Iranian shipping source familiar with the waters.

“When it is very bumpy, they [armed forces onboard] cannot shoot,” the source said.

They are also ill-equipped to go head-to-head with a warship, and would likely suffer “very heavy casualties” in any direct assault on one, said Jeremy Binnie, a Middle East specialist at defense intelligence company Janes.

“Even if they tried to saturate the ship’s defenses by attacking from multiple directions, they would be extremely vulnerable to the air support that would be called in,” he said.

On paper, guided missile strikes would easily destroy these boats, but shoulder-fired missile launchers would pose a threat to low-flying US aircraft, Binnie said.

“It is going to be much harder to eliminate the small boat threat than it was to destroy Iran’s larger naval vessels, which were big targets that were relatively easy to find and track and, at most, only had a limited ability to defend themselves from air attack,” he said.

The reality for the shipping sector is further disruption as well as elevated insurance costs.

After the so-called “tanker war” of the 1980s, Iran increasingly used asymmetric tactics as the Iranian navy was effectively destroyed, much as it has been in the current conflict, said Duncan Potts, a director with consultancy Universal Defense and Security Solutions and a former British Royal Navy vice admiral.

“When the US Navy and the president say, ‘We’ve destroyed the navy, we’ve sunk a frigate off Sri Lanka’ – you’ve done that before, but you’ve forgotten that your opposition here went asymmetric. And they’ve perfected it.”

British Prime Minister Keir Starmer said on Thursday he was “increasingly concerned” about a growing use of proxies by foreign states to carry out attacks in Britain, pledging to bring forward new legislation following recent attacks.

London has seen a string of attacks – mostly arson – on Jewish-linked sites in recent weeks. Some of these are being investigated by counter-terrorism officers, although police say they are not currently being treated as terrorist incidents.

British authorities have increasingly pointed to hostile state activity as part of the backdrop to recent incidents, warning that foreign governments may seek to operate through criminal networks or proxies to maintain deniability.

“I’m increasingly concerned that a number of countries are using proxies for attacks in this country,” he said, speaking after meeting members of the Jewish community at Kenton United Synagogue, which was the target of an arson attack last Sunday.

The fire caused minor smoke damage to an internal room and there were no injuries. A 17-year-old British boy pleaded guilty on Tuesday to arson not endangering life in connection with the incident.

“We have to deal with malign state actors,” Starmer said, adding that it would require legislation by the government.

“I want this country to be a place where everybody feels safe and secure. This is not just a battle for the Jewish community,” Starmer said. “It is our battle. The Britain that I want is a Britain where people can practice their religion, their faith, in safety and security.”

British counter-terrorism police on Wednesday made two further arrests over an alleged plot to carry out an arson attack on a Jewish-linked site in London.

Detectives arrested two men aged 19 and 26 in Watford, northwest of London, on Tuesday, police said. Both remain in custody.

Police did not name a specific location but said the intended target was connected to the Jewish community.

Seven other people arrested earlier in the investigation have since been released on bail, London’s Metropolitan Police said.

British police have been investigating the string of attacks as part of a wider rise in antisemitic threats and criminal activity since the outbreak of the Israel-Hamas war in Gaza in October 2023.

The son of the former Shah appealed to Western countries to join the war against Iran and criticized the decision of the German government not to meet him during his visit to Berlin on Thursday.

Reza Pahlavi, whose father was deposed in the revolution that brought Ayatollah Ruhollah Khomeini to power in 1979, accused Europe of standing by and allowing the Tehran government to continue the bloody repression of protests that killed thousands at the end of last year.

“The question is not whether change will come. Change is on the way,” he told a press conference in Berlin. “The real question is how many Iranians will lose their lives while the community of Western democracies continue to merely watch.”

Demonstrations by both supporters and opponents were held in central Berlin and a person was detained after Pahlavi, who made an appearance, was spattered with some form of red liquid.

POTENTIAL OPPOSITION LEADER

Pahlavi, who has spent most of his life in exile, emerged as a potential opposition leader after anti-government protests erupted in Tehran and other Iranian cities last year.

But Iran‘s opposition movements are deeply divided and many Western governments have been cautious about offering their endorsement because it remains unclear what support he enjoys, almost half a century after his father’s reign was overturned.

European countries, including Germany, have ruled out joining the United States and Israel, which opened the war on Feb. 28 with a wave of airstrikes that killed Iran‘s Supreme Leader Ayatollah Ali Khamenei.

Pahlavi’s visit to Germany came as efforts to end the conflict appear to have stalled, with Iran and the United States both maintaining blockades of the vital Strait of Hormuz, the conduit for around a fifth of the world’s oil.

He said it was a shame that Chancellor Friedrich Merz’s government had not offered a meeting during his visit to Germany.

“Exercise your prerogative. As democracies, you’re entitled to talk to whoever you want,” he said.