On April 13, 2026, the United States Navy began enforcing a blockade of all maritime traffic entering and exiting Iranian ports, targeting Tehran's remaining oil export revenue of approximately 2 million barrels per day. The move triggered immediate turmoil in global energy markets, with WTI crude oil surging about 5% to above $94 per barrel, while the Dow Jones Industrial Average fell 246.90 points to 47,669.67.
Blockade Details and Execution
U.S. Central Command (CENTCOM) ordered the blockade in accordance with a presidential directive following the collapse of peace talks in Islamabad, Pakistan. The blockade applies to vessels of all nations calling on Iranian ports along the Arabian Gulf and Gulf of Oman, but ships transiting the Strait to or from non-Iranian ports in the UAE, Saudi Arabia, or other Gulf states are free to pass. President Donald Trump announced the action on Truth Social, saying the U.S. Navy would “immediately” block ships trying to enter or leave the Strait of Hormuz, accusing Iran of collecting illegal tolls on passing vessels. He warned that any Iranian forces firing on U.S. ships or commercial traffic would be “BLOWN TO HELL.”
CENTCOM stated the blockade will remain in force until Iran returns to negotiations, with no fixed end date. Analysts note that the operation requires multiple carrier strike groups for air cover, dozens of destroyers and frigates, and support from regional allies. The Strait's narrow waters expose U.S. forces to significant threats from Iranian anti-ship missiles, drones, fast-attack boats, and mines, making enforcement a high-stakes proposition from day one.
Market and Geopolitical Impact
Energy markets reacted swiftly: Brent crude rose approximately 6% to above $100 per barrel, and wholesale gasoline prices also moved higher. In equity markets, the NYSE Composite dropped 29.54 points to 22,704.96, while the Nasdaq added 46.79 to hit 22,949.69, and the S&P 500 edged up 0.67 to 6,817.56, reflecting investor uncertainty over the escalating risk.
Iran's Islamic Revolutionary Guard Corps called the move an “act of piracy” and illegal under international law. Iranian officials warned that “no port in the Persian Gulf or Gulf of Oman will be safe” if Iranian ports are targeted, reaffirming their position that the Strait is “either for everyone or for no one.” Tehran also insisted diplomacy remains the only legitimate path forward.
International Reactions and China Tariff Threat
Several Gulf states and mediators, including Oman, have flagged escalation concerns. The United Kingdom has not confirmed the minesweeping role Trump attributed to it, while European leaders distanced themselves from any interpretation suggesting a full Strait closure. Meanwhile, Trump also stated that China would face a 50% tariff on all goods exported to the United States if caught arming Iran, further escalating trade tensions between the two largest economies.
The blockade stems from Iran's effective control of the Strait since the outbreak of the U.S.-Israel-Iran war on Feb. 28, 2026, which had restricted and tolled traffic, paralyzing roughly one-fifth of global oil and LNG shipments. Washington aims to cut off Tehran's remaining oil revenue while keeping the Strait open for other commercial traffic. The legal status of the blockade remains contested, with debate over whether belligerent rights in an armed conflict apply or whether peacetime international navigation law takes precedence.