Tehran has intensified its maritime claims in the Strait of Hormuz, raising the prospect of direct confrontation with international naval forces. The Islamic Revolutionary Guard Corps (IRGC) announced on Tuesday the seizure of two oil tankers, one flagged to Panama and the other to the Marshall Islands, citing “environmental violations” and “illegal entry”. The move is seen as a deliberate escalation in a long-running dispute over freedom of navigation through the critical chokepoint.
The Strait of Hormuz, a 21-mile-wide waterway linking the Persian Gulf to the Gulf of Oman, carries roughly 20% of the world’s oil supply. Iran has long asserted its right to control traffic through the strait, but its latest actions go beyond rhetoric. The IRGC has issued a new set of navigational warnings requiring all vessels to obtain prior permission from Iranian authorities before transiting. Shipping companies and diplomatic sources have confirmed that at least six other tankers were redirected or delayed over the past week.
The United States Fifth Fleet, based in Bahrain, condemned the measure as a “blatant violation of international law”. A spokesman for the fleet said that the United States and its allies “will ensure freedom of navigation through the strait in accordance with the law of the sea”. Britain’s Foreign Office echoed the sentiment, urging Iran to “de-escalate and abide by its international obligations”. The Royal Navy has increased its presence in the region, with HMS Montrose on standby.
The escalation comes at a time of heightened tension between Iran and the West over the renewal of the Joint Comprehensive Plan of Action (JCPOA), the 2015 nuclear deal. Talks in Vienna have stalled since August, with Iran demanding the removal of all sanctions and guarantees that future US administrations will not withdraw again. The IRGC’s latest manoeuvre is widely interpreted as an attempt to force a diplomatic concession or to test the resolve of the incoming Biden administration.
For global shipping, the immediate impact has been a sharp rise in insurance premiums for vessels passing through the strait. The London insurance market has designated the region a “high-risk zone”, adding an estimated $50,000 to $100,000 per voyage. Oil prices rose by 2.5% on Tuesday, with Brent crude trading at $82 a barrel. Analysts warn that a sustained disruption could trigger a spike in global inflation and economic uncertainty.
The legal basis for Iran’s action is contested. The 1982 United Nations Convention on the Law of the Sea (UNCLOS), to which Iran is a signatory, guarantees the right of transit passage through straits used for international navigation. Iran argues that its domestic laws require environmental protection measures that override UNCLOS obligations, a position rejected by the majority of the international community.
The situation echoes previous confrontations, notably the 2019 seizure of the Stena Impero and the 2020 harassment of commercial vessels. However, the scale and coordination of the current operation suggest a more deliberate strategy. Diplomats in the region say that Iran is seeking to renegotiate the terms of its maritime sovereignty, using the strait as a bargaining chip.
The United Nations Security Council is scheduled to hold an emergency session on Thursday at the request of the United States and the United Kingdom. A diplomatic resolution remains uncertain, with Iran showing little sign of backing down. In the meantime, the world’s oil supply and the stability of the global economy rest on a narrow stretch of water subject to a rising tide of geopolitical risk.
