On July 4, British marines and police authorities of Gibraltar, a territory of the UK, seized an Iranian supertanker, the Grace 1, purportedly en route to deliver about 2 million barrels of Iranian oil to Syria. Gibraltar asserted that it acted on request of the UK, on the grounds that oil shipments to Syria violated EU sanctions on the Assad regime. U.S. officials, particularly National Security Adviser John Bolton, applauded the seizure, amid reports that the United States had pressured UK authorities to request it as part of enforcing the Trump Administration’s ‘maximum pressure campaign’ against Iran. Iranian oil shipments to Syria are a core part of Iran’s efforts to assist the Assad regime against its armed rebellion. U.S. sanctions penalize Iran’s oil sector but do not require any state to seize Iranian oil shipments on the high seas.
The UK move against the tanker, whether directly instigated by the United States or not, immediately drew the UK into the broader tensions between the U.S. and Iran. Iran protested the seizure and threatened UK shipping in the Gulf, building on the broader threats against Gulf shipping Iran has made in response to newly-added U.S. sanctions. Iran implemented this latest threat on July 10 when five Islamic Revolutionary Guard Corps Navy (IRGCN) vessels attempted to stop the UK oil tanker British Heritage in the Gulf, abandoning that effort after being driven off by a threat of deadly fire by an escorting British naval vessel. The UK subsequently sent an additional warship to the Gulf to escort UK shipping in the waterway, supporting the U.S. effort to organize a multilateral effort to protect international shipping from further Iranian attacks. The UK has since sought to de-escalate the dispute with Iran by offering to return the seized tanker if Iran pledged not to deliver the oil to Syria; UK Foreign Secretary Jeremy Hunt told Iran’s Foreign Minister Mohammad Javad Zarif that the UK concern is ‘the destination, not the origin’ of the oil.
The UK-Iran dispute occurs amid not only heightened U.S.-Iran tensions but also burgeoning differences between the European Union and Iran over the preservation of the 2015 multilateral nuclear agreement. Iran has recently violated some aspects of the deal, attempting to pressure the EU to provide Iran with the promised economic benefits of the deal. The Trump administration, which abandoned the deal in 2018, argues that Iran’s recent violations of the accord constitute grounds for the EU to abrogate the deal and reimpose all prior EU and United Nations sanctions. Despite the dispute with Iran over the Grace 1 seizure, the UK continues to support preserving the nuclear deal—a position reiterated at an EU meeting on July 15. The EU countries, including the UK, judge that abrogating the deal entirely will bring the United States and Iran closer to a war that will undoubtedly affect Europe directly. Even if European forces do not join any fighting, a major conflict involving Iran will cause another flood of refugees into Europe and could make Europe an arena for Iranian terrorist attacks. Still, neither the UK nor other European states have yet advanced a clear roadmap to providing Iran with the economic benefits of the nuclear deal to satisfy Iranian demands.
The IRGCN assault on the British Heritage also reflects the confidence of Iran’s leadership in its strategy of undertaking provocative acts to pressure Europe and the United States to ease crippling sanctions. Iran’s assessment that such provocations would not trigger U.S. or other retaliation was reinforced by President Trump’s last-minute cancellation of a retaliatory strike for the June 20 Iranian downing of a sophisticated U.S. unmanned aerial surveillance vehicle. Iran’s leaders judge that the Trump administration calculatesthat war with Iran would inevitably spread well beyond the Middle East and potentially sink Trump’s re-election prospects. To illustrate the likelihood that any U.S. war with Iran would engulf the entire region, in mid-July, Iran and its allies sought to highlight these risks.
