The U.S. military’s naval blockade of Iran took effect at 10:00 a.m. Eastern on Monday, cutting off sea access to all Iranian ports and coastal areas as part of President Donald Trump’s escalating pressure campaign against the regime in Tehran.
U.S. Central Command confirmed the blockade in a statement Sunday, saying the measure would be “enforced impartially against vessels of all nations entering or departing Iranian ports and coastal areas, including all Iranian ports on the Arabian Gulf and Gulf of Oman.” CENTCOM added that freedom of navigation through the Strait of Hormuz to and from non-Iranian destinations would not be blocked, and advised ships in the region to monitor maritime broadcasts and contact U.S. naval forces when operating in the Gulf of Oman and Strait of Hormuz approaches.
UK Maritime Trade Operations issued a separate alert Monday confirming that access to Iran’s ports and oil terminals was now restricted across the full Iranian coastline, including locations along the Arabian Gulf, Gulf of Oman, and the Arabian Sea east of the Strait of Hormuz. The bulletin noted that neutral vessels currently docked at Iranian ports had been given “a limited grace period to depart.”
The economic toll could be severe. Miad Maleki, a senior fellow at the Foundation for Defense of Democracies whose family is from Iran, estimated Sunday that the blockade “would cost Iran approximately $276 million per day in lost exports and disrupt $159 million per day in imports, a combined economic damage of about $435 million per day, or $13 billion per month.”
Maleki said Iran has no viable alternative overland or pipeline route to export its oil and petrochemical products, and only roughly 10 percent of non-oil trade could realistically evade the blockade. He noted that Iran’s fuel storage capacity is about 60 percent full and that the regime would need to begin shutting down oil wells in approximately 13 days. Once shut down, the wells degrade quickly due to water seepage.
“Forced shut-ins could permanently destroy 300,000 to 500,000 barrels per day of production capacity,” Maleki calculated. “That’s $9 billion to $15 billion per year in revenue, gone forever.”
He described the overall economic picture as potentially triggering “terminal hyperinflation,” noting that Iran recently issued the largest banknote in its history, the 10 million rial note, which is worth roughly $7 in U.S. currency. A January uprising against the regime, since suppressed, was triggered in part by the earlier collapse of the rial.
“The blockade makes continued resistance economically impossible,” Maleki wrote.
