How Risky Is Iran's Move to Double Down on Pressure via Hormuz?

War has reignited after Iran attacked at least three commercial vessels in the Strait of Hormuz last Tuesday, according to claims by US officials and international maritime authorities. The attack targeted a Saudi Arabian oil tanker and a Qatari liquefied natural gas (LNG) carrier. The incident prompted the United States to revoke temporary sanctions waivers on Iranian oil exports. The waiver was one of the major concessions in a memorandum of understanding (MoU) agreed upon by the United States and Iran last month, which had allowed Tehran to resume oil exports after its tanker fleet was trapped by a US Navy blockade. In retaliation, US Central Command (CENTCOM) stated on Wednesday that it had struck more than 80 targets in Iran, including air defence systems, radar, and over 60 fast-attack craft belonging to the Islamic Revolutionary Guard Corps (IRGC) used to disrupt shipping. The US military announced on Thursday (9/7) that it had launched a new wave of strikes against approximately 90 targets in Iran. CENTCOM said the operation aimed to “impose enormous costs for the targeting and attacking of commercial vessels crewed by innocent civilians in international shipping lanes.” Iran subsequently retaliated by launching new missile attacks against several Gulf states. Air raid sirens and explosions were reported in Bahrain and Kuwait, with further attacks reported on Thursday. Responding to the escalation, maritime security firm MARISKS warned that the tit-for-tat actions “mark a return to direct military confrontation.” Ahead of the NATO summit in Turkey, US President Donald Trump declared the MoU with Iran was now “over,” adding, “Dealing with them [Tehran] is just a waste of time.” Meanwhile, China and Qatar called for de-escalation, and German Defence Minister Boris Pistorius urged Tehran to halt provocations against Washington and end attacks on merchant ships. Iran is seeking to maintain its control over the Strait of Hormuz, a sea lane through which roughly one-fifth of the world’s oil and gas exports from the Gulf region passed before the war. Iran effectively closed the strait after US and Israeli airstrikes killed several senior officials, including spiritual leader Ayatollah Ali Khamenei, on 28 February. Tehran subsequently attacked around a dozen ships trapped in the strait before a fragile ceasefire deal was reached last month. In the days leading up to Tuesday’s attack, peace talks had shown virtually no progress on outstanding issues, including the long-term lifting of US sanctions and Iran’s nuclear ambitions. Iran has repeatedly used Hormuz as a bargaining chip in negotiations when diplomatic channels stall. Tehran has also launched attacks against Gulf states such as Saudi Arabia, the United Arab Emirates, and Qatar. For Tehran, attacking major oil-producing nations that are key US allies is a way to pressure Washington and spread instability so that the wider Middle East feels the impact of the war. Repeated US and Israeli strikes have crippled much of Iran’s military might. However, rather than engaging in conventional warfare, Tehran is waging asymmetric warfare by targeting strategic US facilities in the Gulf and blockading the world’s oil route. Although it does not legally own the Strait of Hormuz, Iran controls the northern coastline, several strategic islands, and a shoreline that allows the IRGC to monitor and threaten passing vessels. Iran uses fast-attack craft, coastal missiles, mines, and drones to target tankers. These tactics have successfully disrupted global energy supplies without engaging in full-scale naval battles. According to various reports, Iran has also begun charging fees of up to 2 million US dollars per ship to guarantee safe passage through Hormuz, a move condemned by maritime experts as illegal. Iran insists vessels must use shipping lanes it has designated in its northern territorial waters, while the US supports using lanes closer to Omani waters. However, Tehran’s leverage is not unlimited. The White House retaliated by imposing a naval blockade in Hormuz, preventing Iranian ships from exporting oil and cutting off one of Iran’s most vital revenue sources. Iran had continued to export oil despite violating US sanctions, mainly to China, at below-market prices. Tehran utilised a shadow fleet of tankers that frequently changed flags, moved without tracking systems, and conducted ship-to-ship transfers to evade detection. Without the sanctions waiver and with the possibility of the US naval blockade being reimposed, Iran now faces significant risks to its battered economy. According to the Washington-based Foundation for Defense of Democracies, the war has caused economic losses amounting to 144 billion US dollars for Iran, plus billions more in lost oil revenue during the blockade. The rial’s exchange rate has also plummeted to an all-time low of around 1.7 million rials per US dollar, while inflation has soared past 88 percent. In its latest statement, MARISKS said the revocation of Iran’s sanctions waiver “erodes the political foundation” of the peace deal and “reduces incentives for continued restraint.” The maritime intelligence firm warned that “the likelihood of further escalation has increased significantly.” Although Trump indicated negotiations would likely continue, he stated that the US would not tolerate attacks on shipping.