The United States formally initiated a naval blockade of Iranian ports on April 13, aiming to halt maritime trade into and out of the country amid ongoing regional tensions. The blockade follows the collapse of recent peace negotiations in Pakistan and represents a strategic effort by the U.S. to exert economic pressure on Iran. While the U.S. stresses that freedom of navigation remains guaranteed for vessels transiting the Strait of Hormuz to and from non-Iranian ports, further enforcement actions have been reported, including intercepted oil tankers reversing course under U.S. naval orders.

U.S. Central Command (Centcom) is deploying more than a dozen warships in the Gulf of Oman and Arabian Sea to maintain the blockade, with additional vessels expected. The aim is to disrupt roughly 90 percent of Iran’s economy, heavily reliant on maritime trade, by restricting its oil exports and other goods. The U.S. has also ended a 30-day waiver on sanctions for Iranian oil already at sea, signaling increased economic pressure. Officials estimate the daily cost to Iran's regime could reach hundreds of millions of dollars, intensifying the strain on a country already facing severe economic difficulties, including high inflation and currency devaluation.

Tehran has condemned the blockade as an act of piracy but has so far refrained from escalating militarily, partly due to a two-week ceasefire agreement established earlier in April. However, Iran’s Islamic Revolutionary Guard Corps (IRGC) has warned it will activate new military capabilities should hostilities resume. The IRGC’s asymmetric naval forces, which include fast attack boats, sea mines, drone swarms, and ballistic missiles, remain a potential threat to U.S. naval operations in the region.

Analysts note that despite damage to Iran’s conventional naval assets from early U.S. and Israeli strikes, Iran retains the ability to challenge U.S. forces through swarming tactics and small boat attacks. Some Chinese military observers suggest that Iran’s numerous small vessels could operate near the Gulf of Oman and the Strait of Hormuz, leveraging concealed positions around dozens of islands to deter U.S. warships from closer engagement. Drones could also provide surveillance and expand Iran’s operational reach across the Persian Gulf.

At the same time, Iran may retaliate in other ways, including missile and drone strikes against Gulf neighbors or proxy attacks on commercial shipping in strategic waterways such as the Red Sea. While the blockade is legal under international law governing naval warfare, it carries substantial risks and costs for the U.S. Navy, including the threat of attacks on static vessels enforcing the blockade.

The enforcement of the blockade underscores a high-stakes contest between the U.S. and Iran, with broader geopolitical implications involving regional actors and global oil markets. Both sides face significant risks, and the situation may hinge on which party yields first amid the escalating pressure and countermeasures.