But in Iran, it has unified Tehran’s squabbling factions against an old adversary, the UK, long an untrustworthy imperial power by both supporters and opponents of the regime.
"The Queen's thieves captive in the strait," the conservative Resalat newspaper declared on Sunday.
The capture of the Stena Impera in the Strait of Hormuz came just 15 days after the UK seized the Grace 1, a tanker filled with Iranian oil, off the coast of Gibraltar in a move that has been decried by the Islamic Republic.
It came hours after a Gibraltar court announced it would hold the ship for another month while its destination were investigated.
On Sunday, Ali Larijani, speaker of Iran's parliament said the Revolutionary Guard seized the oil tanker as a direct response to the "theft" of the Grace 1 by British forces.
"The British stole a ship, and the IRGC responded to them,” Mr Larijani, who has the ear of both Supreme Leader Ali Khamenei and President Hassan Rouhani, was quoted as saying by local media.
Iran’s parliament, often engaged in factional infighting, issued a statement thanking the Revolutionary Guard for seizing the Stena Impero.
"Tanker for tanker; Iran acted on its pledge," the newspaper Keyhan, whose editor is appointed by Mr Khamenei, said on its front-page.
"The seizure of an oil tanker for the capture of an oil tanker," the pro-reform newspaper Ebtekar said in a front page headline, with another reformist-leaning newspaper praising Iran’s “diplomacy of power.”
The seizure of the UK-flagged ship by the Revolutionary Guard appears to signal a more aggressive posture by Iran in the crisis rooted in US president’s Donald Trump’s withdrawal last year from the landmark nuclear deal and vow to prevent international buyers from purchasing Iran’s oil.
Iran gave other partners in the nuclear deal a year to circumvent the US sanctions but grew angry as its oil exports collapsed. Iran began launching alleged attacks on Gulf shipping, targeting US allies Saudi Arabia and the United Arab Emirates, almost a year after Mr Trump scuttled US participation in the nuclear deal.
The seizure of the Grace 1, on accusations it was violating EU sanctions by transporting oil to Syria, added to Tehran’s suspicions that the UK and other European supporters were quietly collaborating with Mr Trump’s “maximum pressure” campaign.
Though the UK has insisted that it was enforcing EU rules by preventing crude from reaching Syrian dictator Bashar al-Assad, Iran insists the oil was not heading to Syria. The EU has yet to speak a word about the Grace 1, even as it voiced support for the UK after the seizure of the Stena Impera.
“Having failed to lure Donald Trump into War of the Century, and fearing collapse of his B-team, John Bolton is turning his venom against the UK in hopes of dragging it into a quagmire,” Iran’s foreign minister Mohammad Javad Zarif wrote on Twitter.
But even as Mr Zarif called for “prudence and foresight and some Iranian news outlets and officials were seeking to downplay the Stena Impera seizure, video released by the Guard showed black-masked Iranian commandos rappelling from a helicopter onto the ship in an apparent emulation of how the seizure of the Grace 1 was described.
Many Iranians fear and oppose any military confrontation with the US or its allies. But with the non-UK crew of the Stena Impera apparently safe and accounted for, few were speaking of war.
Britain’s junior defence minister Tobias Ellwood said the UK may pursue sanctions against Iran for the seizure, though it remains unclear what such restrictions would entail as Britain has mostly avoided trade with Iran since the re-imposition of US sanctions.
"We are going to be looking at a series of options,” he told Sky News. “We will be speaking with our colleagues, our international allies, to see what can actually be done."
Iran can also count on Russia and China to protect it at the UN Security Council. On 24 June, the Security Council condemned escalating attacks on Gulf shipping but declined to single out Iran.
Adding to confusion over the ships, some Iranian officials continued to insist the Stena Impera was stopped for allegedly violating maritime rules. Allah-Morad Afifipour, a maritime official, told state television the ship and its 23-member Russian, Indian, Phillipine, and Latvian crew were seized after the tanker struck an Iranian fishing boat, and would be subject to an investigation.