The United States military began a blockade of all maritime traffic entering and exiting Iranian ports on April 13.
The operation follows an announcement by President Donald Trump on April 12, stating that the blockade would be implemented after American and Iranian negotiators failed to reach an agreement during a meeting in Islamabad.
Maritime Enforcement and Geography
The enforcement of a total blockade on Iranian ports requires control over the Strait of Hormuz, the primary maritime artery connecting the Persian Gulf to the Gulf of Oman and the open ocean. At its narrowest point, the strait is approximately 21 miles wide, forcing the majority of shipping traffic through narrow inbound and outbound lanes.
Iranian maritime trade is concentrated in several key hubs, most notably Bandar Abbas, which serves as the country’s primary commercial port. A blockade of this scope involves the interception of commercial tankers, cargo vessels and naval ships attempting to transit the strait or enter Iranian territorial waters.
Global Economic Implications
The restriction of maritime traffic in the Persian Gulf affects the global supply of petroleum and liquefied natural gas. A significant percentage of the world’s seaborne oil passes through the Strait of Hormuz, making the region a critical choke point for global energy markets.
Beyond energy, the blockade disrupts the movement of essential goods and commercial imports into Iran, impacting the operational capacity of Iranian ports and the logistics of international shipping companies that utilize these routes.
Legal and Strategic Framework
The legality of a naval blockade is governed by international maritime law and the San Remo Manual on International Law Applicable to Armed Conflicts at Sea. Under these standards, a blockade must be declared, notified to all belligerents and neutral states, and effectively maintained to be recognized as legal.
Military analysts are currently evaluating the practicalities of maintaining a total blockade, including the resource requirements for continuous surveillance and the risks of direct engagement with the Islamic Revolutionary Guard Corps Navy (IRGCN), which operates a large fleet of quick attack craft designed for asymmetric warfare in the shallow waters of the Gulf.
The Iranian government has not yet issued a formal diplomatic response to the commencement of the blockade.
