US Navy Enforces Total Blockade of Iranian Ports as Oil Prices Surge Past $100

The United States naval blockade of Iranian ports in the Strait of Hormuz entered its second day on Tuesday, April 15, 2026, with limited but measurable effect on shipping traffic, as six merchant vessels turned back under U.S. orders while at least four ships linked to Iran crossed the passage despite the restrictions. The blockade, ordered by President Donald Trump and in effect since noon on Monday, April 13, is enforced by more than 10,000 U.S. military personnel and over a dozen warships, according to U.S. Central Command. The operation has drawn sharp condemnation from China and the International Maritime Organization, while oil prices surpassed $100 per barrel in the wake of the announcement.

The Strait of Hormuz has long been a focal point of U.S.-Iran tensions, given that a significant share of the world's crude oil transits through the passage. The current military confrontation between the United States and Israel against Iran began on February 28, 2026, under the operation designated Epic Fury, during which Supreme Leader Ali Khamenei was killed. His son, Mojtaba Khamenei, was appointed Supreme Leader on March 9, 2026. Ceasefire talks between Washington and Tehran held in Islamabad concluded without progress, according to reporting cited in source articles. Iran has since been reported, according to sources including Kpler, Bloomberg, and the Financial Times, to be formalizing a system that would effectively transform the strait into a managed maritime toll route.

Ships cross despite blockade, spoofing suspected The first full day of the blockade produced a mixed operational picture. According to Reuters navigation data cited by Il Fatto Quotidiano, at least eight vessels crossed the Strait of Hormuz on Tuesday, including three oil tankers traceable to Iran, though those tankers were not headed toward Iranian ports and were therefore not subject to the restrictions. BBC Verify, using open-source intelligence and data from the tracking portal MarineTraffic, identified four specific vessels linked to Iran or under U.S. sanctions that crossed the strait: the bulk carrier Christianna, which had called at the Iranian port of Bandar Imam Khomeini; the Rich Starry, sanctioned by the United States for trade with Iran, which sailed east from Sharjah in the United Arab Emirates; the tanker Murlikishan, also under U.S. sanctions, which crossed heading west after departing the Chinese port of Lanshan; and the tanker Elpis, which crossed heading east from the Iranian port of Bushehr. BBC Verify noted that these vessels may have transmitted false position signals — a practice known as spoofing — to mask their actual locations. Industry sources told Reuters that overall flows through the strait remain drastically reduced compared to the more than 130 daily crossings recorded before the conflict began.

IMO warns of 1,600 stranded vessels, China threatens countermeasures The international response to the blockade was swift and critical. Arsenio Dominguez, Secretary-General of the International Maritime Organization, declared that the naval blockade violates international law and, according to El Mundo, warned that approximately 1,600 vessels carrying around 20,000 sailors remain stranded in the Persian Gulf amid the escalating tensions. Chinese Foreign Ministry spokesperson Guo Jiakun called the blockade "dangerous and irresponsible" at a press conference, arguing that U.S. military operations would only exacerbate tensions and undermine what he described as a fragile ceasefire agreement.

„The United States has intensified military operations and undertaken a targeted blockade action, which will only exacerbate tensions and undermine the already fragile ceasefire agreement, further jeopardizing the safety of passage through the strait.” — Guo Jiakun via ANSA

China also pushed back against U.S. allegations that Beijing is supplying weapons to Iran, with Guo Jiakun stating that such reports "are completely fabricated," and warned that if Washington used those allegations as a pretext to impose additional tariffs on Chinese goods, Beijing would adopt "resolute countermeasures."

„If the United States insists on using this as a pretext to impose additional tariffs on China, China will certainly adopt resolute countermeasures.” — Guo Jiakun via ANSA

Selective enforcement likely as insurance costs stay extreme Military and academic analysts cautioned that the blockade's practical enforcement remains uncertain and potentially selective. CENTCOM clarified that the measure applies only to vessels entering or leaving Iranian ports and coastal areas, and explicitly stated that freedom of navigation for ships transiting the strait to and from non-Iranian ports would not be obstructed. U.S. defense officials told domestic media that two destroyers crossed the strait to monitor Iranian ports with radar, though analyst Louis Borer of Risk Intelligence noted that blocking the passage entirely would require a significantly larger military deployment. Fabrizio Coticchia, professor of political science at the University of Genoa, told Il Fatto Quotidiano that Washington could opt for selective enforcement, noting that an intermittent blockade is operationally feasible without stopping every ship or entering the strait. War-risk insurance premiums have not risen further compared to previous days but remain at very high levels — hundreds of thousands of dollars per week — with coverage reviewed every 48 hours, according to maritime brokerage firm BRS. BRS assessed that a return to normalcy appears increasingly distant, and that commercial traffic in the strait could be reduced to a minimum or zero in the short term. Oil prices have already crossed $100 per barrel, and Iran is reported to be formalizing a proposal that would transform the strait into a permanent maritime toll system, with payments potentially denominated in currencies other than the U.S. dollar.

Turned back to Iranian ports: 6, Crossed strait (linked to Iran/sanctioned): 4, Total crossings recorded (Tuesday): 8