Strait of Hormuz blockade and other major naval sieges in modern times

A "shadow fleet" of vessels successfully bypassed a US naval blockade of the Strait of Hormuz between March 1 and April 15, 2026, following an escalation of conflict involving Iran. This covert network of ships utilized fake flags, shell companies, and disabled tracking signals to navigate the vital waterway, which is crucial for global oil transport. The blockade was imposed by the United States on April 13 after Iran threatened to block enemy ships. Despite the blockade, an investigation tracked 202 voyages by 185 vessels through the strait, demonstrating Iran's ability to evade international maritime restrictions. This operation occurred amidst fears of attacks and disruptions to navigation in the strait, a chokepoint for a fifth of the world's oil.

President Donald Trump has warned Iran to comply with US demands regarding its nuclear program, stating that a US naval blockade could continue for months. Trump conveyed this message on Wednesday, reportedly after rejecting Iran's latest proposal to reopen the Strait of Hormuz. He urged Iran to "get smart soon" and indicated a willingness to extend economic pressure. The US naval blockade is aimed at compelling Iran to accept tighter controls on its nuclear activities. Trump's remarks were made via his social media platform, accompanied by a graphic image.

Suspected pirates have reportedly hijacked the cargo vessel Sward off the coast of Somalia, steering it towards the Somali coastline. The incident, which occurred on Monday, involved nine armed individuals boarding the ship carrying cement from Suez, Egypt, to Mombasa, Kenya. The Sward, flying the flag of St Kitts and Nevis, has a 15-person crew consisting of two Indian nationals and 13 Syrians. This is the second such hijacking off Somalia in less than a week. The attacks are occurring amidst existing maritime route disruptions caused by the blockage of the Strait of Hormuz. Pirate activity has resurfaced in the region following a decline in anti-piracy patrols and a shift in resources to counter Houthi rebel threats.

Pakistan has opened six overland transit routes to Iran to facilitate trade amid disruptions caused by US-Iran tensions and a blockade of the Strait of Hormuz. The initiative, formalized on April 25, 2026, allows goods from third countries to be transported through Pakistan to Iran by road, addressing the issue of thousands of stranded containers at Karachi port. These routes connect Pakistan's major ports, including Karachi and Gwadar, with Iranian border crossings in Balochistan. The move aims to promote regional trade and position Pakistan as a key trade corridor. The announcement occurred during Iranian Foreign Minister Abbas Araghchi's visit to Islamabad, where Pakistan is seeking to mediate an end to the conflict between the US and Iran. The transit order does not include Indian-origin goods.

Iran may be forced to cut oil production if the US naval blockade of the Strait of Hormuz persists, according to experts. Analysis suggests Iran could exhaust its crude oil storage capacity within 12 to 22 days. The Strait of Hormuz, a vital waterway for global oil and LNG supplies, has been partially or fully restricted by Iran since February 28, coinciding with air strikes by the US and Israel. Iran claims the security of the strait is not free and links its openness to the lifting of US restrictions on its oil exports. The US naval blockade began on April 13, leading to concerns about Iran's ability to export its oil and manage its storage levels.

The US military, through CENTCOM, announced it will blockade all Iranian ports starting Monday, April 13th, at 10 am Eastern Time, impacting all maritime traffic entering or exiting. This action follows unsuccessful peace talks in Pakistan and aims to exert pressure on Tehran. While the blockade targets vessels of all nations using Iranian ports, CENTCOM stated it will not impede vessels transiting the Strait of Hormuz to and from non-Iranian ports. Iran has warned that any approaching military vessels will be breaching the ceasefire. The announcement has already impacted oil prices, with US crude jumping 8 percent. The blockade comes after Iran effectively took control of the Strait of Hormuz following the start of war with the US and Israel on February 28th.

Under the Trump administration's blockade of Iranian ports, a U.S. destroyer interdicted two oil tankers attempting to leave Iran on Tuesday. The tankers had departed from Chabahar port in the Gulf of Oman before being contacted by the U.S. warship. U.S. Central Command (CENTCOM) reported that six vessels complied with orders to return to an Iranian port in the Gulf of Oman. The U.S. military is enforcing the blockade against all nations' vessels entering or leaving Iranian ports. According to CENTCOM, the blockade aims to halt Iran's maritime trade, which supports a significant portion of the country's economy.

A Chinese tanker, the Rich Starry, retreated twice in 48 hours from the Strait of Hormuz, where a US naval blockade is in effect. The vessel, which is sanctioned by the US and flies the flag of Malawi, initially approached the strait on Monday after departing from the UAE, but turned back shortly before entering. On Tuesday, it entered the Gulf of Oman before making a U-turn and anchoring near Iran's Larak Island by Wednesday evening. The Rich Starry is reportedly carrying approximately 250,000 barrels of methanol acquired in the UAE. Analysts suggest that the incident reflects the risks commercial vessels face due to the blockade, with no ships receiving preferential treatment.

Despite a newly imposed US blockade on ships calling at Iranian ports, at least three tankers transited the Strait of Hormuz on Tuesday. These vessels were not heading to Iran and therefore not directly affected by the blockade. One tanker, the Panama-flagged Peace Gulf, is transporting Iranian naphtha to the UAE. Two US-sanctioned tankers, Murlikishan and Rich Starry, also passed through the strait. Murlikishan is heading to Iraq to load fuel oil, while Rich Starry, sanctioned for dealing with Iran, exited the Gulf carrying methanol after loading cargo in the UAE. The US blockade was announced after failed peace talks between the US and Iran in Pakistan.

The article discusses the possibility of a US blockade of Iran, focusing on its feasibility and potential advantages over other military actions. According to retired US Rear Admiral Mark Montgomery, a blockade of vessels entering and exiting the Gulf is achievable and less risky than directly confronting Iranian forces in the Strait of Hormuz. A blockade would allow US warships to operate safely offshore, tracking and intercepting vessels. The US Navy possesses the necessary assets, including special forces, helicopters, and fast boats, to conduct such an operation, as demonstrated by previous blockades of Venezuela and Cuba, and the seizure of the Russian oil tanker Marinera. The article highlights that while the US has the capability, the ultimate goal and effectiveness of a blockade remain open questions.

On April 14, 2026, the United States implemented a naval blockade of Iran to pressure the country into accepting terms to end their ongoing war. Iran's armed forces have condemned the blockade as an illegal act. The blockade threatens Iran's oil revenue, as approximately 80% of its exports pass through the Strait of Hormuz. While Iran had been controlling access to the Strait, allowing only select countries to pass, it continued to export its own energy products. In March and early April, Iran's oil exports actually increased, reaching 1.84 million barrels per day in March. The price of Iranian oil has remained above $90 per barrel in the past month.

Oil prices rose above $100 per barrel on Monday after ceasefire talks between the U.S. and Iran failed to end their ongoing war, which began in late February. Despite the breakdown in negotiations, U.S. stock markets remained relatively stable, suggesting cautious optimism about the conflict's potential impact on the global economy. The S&P 500 was virtually unchanged, while the Dow Jones Industrial Average was down 0.5% and the Nasdaq composite rose 0.3%. President Trump threatened a blockade of the Strait of Hormuz in response to the failed talks, aiming to restrict Iran's oil revenue. Iran retaliated by threatening all ports in the Persian Gulf and the Gulf of Oman. The Strait of Hormuz is a crucial waterway for global oil transport.