Will the release of the Adrian Darya-1 affect US-UK relations?

Arguably, the seizure of the Adrian Darya-1 marked the moment when the UK became directly involved in the ongoing US-Iran conflict. It was clear that Tehran would not remain silent. So when Gibraltar extended the tanker's detention last month, the Iranians responded and seized the British-flagged tanker Stena Impero, putting the UK government under pressure to respond.

Then-UK Foreign Secretary Jeremy Hunt suggested that there should be a European-led mission to protect shipping in the Persian Gulf region. However, that proposal has since been ruled out by the government of new UK Prime Minister Boris Johnson. Instead, the UK has decided to join a US-led mission in responding to Iranian threats, part of Johnson's overall rebalancing of UK foreign policy in Washington's direction.

The decision to release Adrian Darya-1 should de-escalate tensions between the UK and Iran slightly. It could prompt the Iranians, because their main disagreement is with the US and not the UK, to release Stena Impero. Tehran must be taking into account the fact that London still supports the 2015 nuclear deal (the Joint Comprehensive Plan of Action or JCPOA), which the US rejected in 2018.

The UK has made it clear that its primary concern regarding Adrian Darya-1 is the transfer of oil to Syria. "We note the Government of Gibraltar has received assurances from Iran that the Grace 1 will not proceed to Syria. Iran must abide by the assurances they have provided. We will not stand by and allow Iran - or anyone - to bypass vital EU sanctions on a regime that has deployed chemical weapons against its own people," a British foreign office spokesman said in a statement.

"There is no comparison or linkage between Iran's unacceptable and illegal seizure of, and attacks on, commercial shipping vessels in the Strait of Hormuz and the enforcement of EU Syria sanctions by the Government of Gibraltar. Freedom of navigation for commercial shipping must be respected and international law upheld," the official continued.

It seems clear that the White House was not delighted by the decision to release the tanker, which came only hours after White House National Security Advisor John Bolton's visit to London. The State Department issued a statement that said the US "assesses that the M/T Grace I was assisting the Islamic Revolutionary Guard Corps (IRGC) by transporting oil from Iran to Syria. This could result in serious consequences for any individuals associated with the Grace I". The statement added that "in the case of the M/T Grace I, we will continue to act consistent with our existing policies concerning those who provide material support to the IRGC".

That statement was followed by reports that a US federal court had issued a warrant to detain the ship pursuant to the State Department's decision in April to designate Iran's Islamic Revolutionary Guard Corps as a "Foreign Terrorist Organization". The US Justice Department argued that the tanker was linked to the IRGC and therefore subject to seizure, but officials in Gibraltar determined that under EU law they had no grounds upon which to hold it.

It's no surprise that the Trump administration opposed releasing Adrian Darya-1. But its opposition increases pressure on London. At a time when Johnson is about to lead the UK out of the EU on October 31, Britain in increasingly dependent on support from the US. A UK-U.S. trade deal is key to the UK's post-Brexit plans, and Johnson would want to minimise tensions between Downing Street and the White House. However, he also does not want to risk the UK becoming embroiled in an unwanted US-Iran conflict.

"Despite her determination to deliver Brexit, Theresa May felt able to disagree with the US on the Iran deal and climate change. Trump was often critical of her. Trump is full of praise for her successor. There is a real danger that Boris will deliver whatever Trump asks, because if Brexit happens the UK will be isolated and desperate for a trade deal with the US," Clare Short, a former International Development Secretary in the Labour government led by Tony Blair said.

"It is very interesting that the Gibraltar courts have made a decision independent of UK influence. This has clearly annoyed the US."

At a time when Johnson is about to lead the UK out of the EU on October 31, Britain in increasingly dependent on support from the US

This is a big test for a new prime minister who, although he supports the nuclear deal, needs to walk a tight line between alienating the US and provoking Iran. What is important to watch now is the extent to which Gibraltar's decision will have an impact on the "Special Relationship".The fact that the US Justice Department fought to have Adrian Darya-1's seizure extended indicates that it was Washington that was behind the decision to detain it in the first place. The hardliners in Trump's administration, seemingly, are attempting to increase international pressure on Tehran. That is probably why Bolton described the seizure of the vessel as "excellent news" on Twitter last month.

"I am not aware of the arguments the US will put to the Gibraltar court to achieve a further detention of the Grace 1, but I would expect them to be rejected by the UK government since they can only be based on a policy the UK rejects; namely, preventing Iran from selling oil at all. So this could well turn into a disagreement between Britain and the US," former British ambassador to Tehran Sir Richard Dalton said on Friday, before authorities in Gibraltar did reject the US warrant.

"But the big things in US and UK diplomacy are NATO, the EU, intelligence sharing and mutual trade and investment. Such matters are not directly connected to Iran policy, which is of secondary importance in the relationship," Dalton added. "The US/UK relationship is so multi-faceted, that one further disagreement can be absorbed and dealt with without much or any harm being done. It will be touched on by Johnson and Trump at the G7 meeting in Biarritz but I suspect only in passing."

One thing that further complicates the UK government's mission is that Britain is dealing with a US administration that does not seem to have an internal political consensus on Iran. While Trump does not appear to be in favour of war, others such as Bolton do appear to favour it. Johnson's government has, therefore, to take a firm position in not letting US pressure drag London into any unnecessary conflicts. That is the only way it can continue maintaining a balanced policy with both Europe and the US in the post-Brexit period.

Abdulaziz Kilani is a British-Arab writer. He is also the editor-in-chief of Sharq Wa Gharb Arabic electronic newspaper.

Follow him on Twitter: @az_kilani

This article was published with permission from Lobelog.

Opinions expressed in this article remain those of the author and do not necessarily represent those of The New Arab, its editorial board or staff.