It was a meticulously planned military assault, executed by British commandos in the dead of night. One group of Royal Marines swooped down from a helicopter while others sped to the scene in patrol boats. But their target was not a military installation but an oil supertanker.
The seizure of the Grace 1 was overseen by Gibraltarian authorities, who suspected that the Panamanian-flagged vessel was on a sanctions-busting mission to deliver crude to a refinery on Syria’s Mediterranean coast. Britain and Gibraltar were careful not to point the finger of blame at any state.
But within hours it triggered the latest diplomatic spat with Iran. Tehran summoned the British ambassador to admonish him, describing the tanker’s seizure as “illegal”. In effect, Iran had claimed responsibility for the tanker and set the stage for the latest stand-off between the Islamic republic and the west.
On Friday, Mohsen Rezaei, a former Revolutionary Guard commander, said on Twitter that if the UK refused to release Grace 1, Iran should seize a British vessel.
Iran has been supplying oil to Syria for years, despite the Arab state being under US and EU sanctions. But it was the first time Iranian oil had been seized, according to Lloyd’s List, the shipping journal, and it comes amid heightened tensions between the Islamic republic and the west as the Trump administration pursues a “maximum pressure” strategy against Tehran.
The risk for the UK is that the Islamic regime perceives Britain to be acting at the behest of Washington — which has vowed to squeeze Iranian crude exports to zero — at a time when London is working with European allies to ease tensions and save the 2015 nuclear deal with Iran.
Spain said Gibraltar, a British overseas territory, had acted after a US request to the UK. The comments were immediately pounced on by the Iranian media.
John Bolton, the hawkish US national security adviser, said the seizure of Grace 1 was “excellent news”. “America & our allies will continue to prevent regimes in Tehran & Damascus from profiting off this illicit trade,” he wrote on Twitter.
Brian Hook, the US envoy on Iran, told reporters last week that Washington had set up a “tanker task force” that “tracks all Iranian tankers”.
British officials have insisted the operation had nothing do with US sanctions on Iran, which the UK does not support. Instead, they said the UK had little choice but to apprehend the Grace 1 once it entered Gibraltar’s waters because it was violating EU sanctions on Syria.
But for European powers the timing is inopportune. Britain, Germany and France are trying to keep alive the nuclear deal, which has been pushed to the brink of collapse since Donald Trump withdrew the US from the accord and imposed stringent sanctions that have strangled Iran’s ability to export oil. And the European signatories to the agreement — known as the E3 — are entering a crunch period as they try to convince Tehran not to increase its nuclear activity and reassure Iranian leaders that they are sincere in their efforts to cushion the economic impact of US sanctions.
Hassan Rouhani, Iran’s president, set the E3 a 60-day deadline that expires on Sunday to come up with steps to provide Iran with economic relief, particularly its ability to sell oil. If not, Tehran warns that it will expand its uranium enrichment processes beyond limits set in the 2015 deal.
“So far, both Iran and Europe have managed to keep a firewall between the JCPOA [nuclear deal] and [other] contentious issues,” said Ellie Geranmayeh of the European Council on Foreign Relations. “What we are seeing in recent weeks is greater strain in relations between Europe and Iran. It’s going to become harder with each incident to keep the firewall intact.”
The UK had sided with the US in blaming Iran for sabotage attacks on oil tankers in the Gulf in May and June in contrast to the more circumspect Germans and French. British officials have also chastised Iran for its regional role, including its military support for Syria and militant groups.
Lloyd’s List said it had tracked five smaller tankers shipping Iranian oil to Syria, which is suffering an energy shortage, since the beginning of May. It added that the vessels had turned their transponders — which allow the tankers to be tracked — on and off to disguise their destination.
But the Grace 1 was the first vessel carrying Iranian oil this year to enter European waters, it said. It is not clear why Iran used such a large vessel — the tanker has a capacity of up to 2m barrels — and sent it through European waters, rather than using smaller tankers on the usual route to Syria through the Suez Canal.
Traders have questioned if this was partly driven by Iran’s need to sell barrels building up in storage tanks as the US sanctions bite.
Chronis Kapalidis, a former naval officer and security expert at Chatham House, said the Iranians could have chosen the European route as a means of distraction. “All ships going through the Suez are highly monitored, whereas if you take the long route you minimise the chances of getting caught,” he said.
Other analysts said the ease at which the vessel could be tracked left the cargo more exposed.
The tanker is now impounded at Gibraltar’s port and will probably become the subject of a lengthy legal process.
“What will be important is for the UK and Iran to quickly resolve this issue diplomatically . . . and avoid this incident further undermining the political [process] needed to salvage the nuclear deal,” said Ms Geranmayeh.