Iran's Supreme Leader Mojtaba Khamenei issued a warning on Saturday as tensions over the Strait of Hormuz escalated dramatically, declaring that Tehran's navy stands ready to inflict "new bitter defeats" on the United States and Israel despite the heavy losses Iran's conventional fleet has suffered during the seven-week conflict. In a message marking Iranian Army Day, Khamenei said that just as Iran's drones have struck US and Israeli targets "like lightning," the Islamic Republic's "valiant navy" remains poised to humble its adversaries once again. "The Islamic Army has exposed those armies' weakness and humiliation to the world," Khamenei wrote in a series of posts on X, adding that Iranian forces are "courageously defending the land, water, and flag that belong to it." The supreme leader's defiance came as Iran announced it was reimposing strict military control over the strait, reversing a brief and limited reopening that had seen a convoy of eight tankers transit the waterway on Friday. According to shipping sources, at least two vessels came under fire while attempting to pass through the narrow chokepoint, underscoring the volatility that persists despite a fragile two-week ceasefire brokered by Pakistan on April 8.
The United States and Israel have dealt devastating blows to Iran's regular naval forces since launching joint strikes on Tehran on February 28, sinking an estimated seventeen warships and destroying hundreds of fast-attack boats. US military officials have declared Iran's conventional navy "largely combat ineffective." But as military analysts have repeatedly noted, the threat to the Strait of Hormuz has not diminished in proportion to those losses. The reason lies in Iran's decades-old strategic pivot toward asymmetric warfare, a doctrine born from the painful lesson of 1988, when the US Navy sank roughly half of Iran's conventional fleet in a single day. In response, Tehran built a parallel naval force under the Islamic Revolutionary Guard Corps (IRGC), designed not to win conventional battles but to impose costs, disrupt shipping, and leverage geography. Today, that force consists of hundreds of small, agile speedboats, many equipped with missiles, rockets, and machine guns. Known as the "mosquito fleet," these vessels can move quickly, disperse easily, and regroup, making them notoriously difficult for large warships to track or target in the narrow, congested waters of the strait. As one military expert noted, even if US defenses stop 90 percent of an incoming swarm, the remaining 10 percent can still cause catastrophic damage to a billion-dollar warship.
Beyond the speedboats, Iran retains a formidable arsenal of naval mines, estimated at between 2,000 and 6,000 units. Although US strikes have destroyed some Iranian minelayers, Tehran still retains approximately 80 to 90 percent of its small craft capable of laying mines, meaning it could feasibly deploy hundreds more devices in the waterway at will. The mine threat has proven so effective that even Iran itself has struggled to locate and remove the mines it laid, creating a chaotic obstacle course that has paralyzed global shipping for weeks. According to The New York Times, Iran chaotically mined the strait using small boats after the war began, likely without recording exact coordinates, and now lacks the technical capability to quickly neutralize them. This self-imposed dilemma has complicated Tehran's own efforts to reopen the waterway, but it has also rendered the strait a no-go zone for any navy lacking advanced mine-sweeping capabilities. To compound the threat, Iran has also deployed shore-based anti-ship cruise missile batteries along the Gulf coast, as well as unmanned surface vessels configured as floating bombs. According to a March 2026 analysis, Iran's asymmetric anti-ship capability comprising hundreds of IRGC fast-attack craft, mobile coastal missile launchers, and mine-laying capacity remains "largely intact" despite the destruction of its conventional fleet.
The geography of the Strait of Hormuz itself amplifies Iran's asymmetric advantage. At its narrowest point, the strait is only 39 kilometers wide, forcing large ships into tight, predictable lanes just two nautical miles wide in each direction. Vessels must transit at slow speeds and execute turns adjacent to Iranian-controlled islands, creating a perfect kill zone for small, fast attackers. A US destroyer, no matter how advanced, cannot simultaneously intercept missiles, counter drone-boat swarms from multiple bearings, sweep for mines, and manage GPS disruption, all while navigating a congested waterway. This operational reality explains why US naval forces have largely remained east of the strait in the Sea of Oman, avoiding the narrow passage where the element of surprise would favour the IRGC. As one US official privately conceded, the geography gives the attacker an inherent advantage that no amount of firepower can fully neutralize. It also explains why Iran's leaders speak with such confidence despite their conventional losses: they understand that holding the strait hostage does not require a blue-water navy. It requires only the credible threat of chaos, and that threat has proven remarkably resilient.
As the two-week ceasefire enters its final days, with President Donald Trump threatening to end the pause unless a long-term deal is agreed, the strategic calculus in the Gulf remains asymmetrical. Iran has already demonstrated its ability to strike US bases across the region with missiles and drones, claiming to have destroyed more than 80 percent of strategic radars at American facilities in the Gulf in a single wave of attacks. The IRGC has stated that it has deployed 800 missiles and 3,600 drones against US and Israeli targets during the current hostilities, and that much of its arsenal remains unused. For all of Washington's firepower, the United States has been unable to force Tehran to reopen the strait, and its naval blockade, announced on April 13 has done little to change that reality. Indeed, Iran's armed forces command said on Saturday that the strait had reverted to a state of "strict Iranian military control," citing what it described as repeated US violations and acts of "piracy" under the guise of the blockade.