Could Iran sink US warships in the Persian Gulf?

Tensions in the Persian Gulf between the US fleet and Iran’s Islamic Revolutionary Guard Corps Navy (IRGCN), also known by its Persian acronym NEDSA, have once again highlighted the potential for clashes or even all-out war. 

Naval warfare analysts who spoke to Rudaw English say the small speedboats used by the IRGCN could pose a genuine threat to America’s carrier fleet deployed in the Gulf. 

US President Donald Trump recently said he has instructed the US Navy to destroy any Iranian boats that “harass” US ships following another tense encounter in which eleven IRGCN boats made “dangerous and harassing approaches”.  

The encounter was certainly not unprecedented. 

The IRGCN relies heavily on unconventional, asymmetric hit-and-run tactics to compensate for the US Navy’s superior size, technology, and firepower. 

In any confrontation, IRGCN speedboats would likely attempt to elude or overwhelm the defenses of US warships to get close enough to damage or even sink them.

“Fast, small boats are a significant threat to US ships in the Persian Gulf,” Bryan Clark, a senior fellow at the Hudson Institute and an expert on naval operations and war-gaming, told Rudaw English. 

“Although US ships have gyro-stabilized guns and helicopters that can attack incoming boats, these defenses could be overwhelmed by swarms of small boats,” he said. 

Some of Iran’s fast boats are also armed with anti-ship missiles which could enable them to hit US warships before they are targeted and destroyed. 

In the US military’s 2002 wargame, dubbed Millennium Challenge, the ‘Blue’ team, which represented the US, suffered heavy losses at the hands of the ‘Red’ team, which represented Iran using asymmetric tactics. 

The ‘Red’ team fired a barrage of missiles and launched an armada of small boats, which dealt a devastating blow against the ‘Blue’ team, sinking 19 warships including an aircraft carrier in just ten minutes. 

Had this played out in real life, the US would have suffered 20,000 fatalities.

Clark doubts such a dire outcome would unfold in the event of a major US-Iran confrontation in the Gulf today. 

“In part because of the Millennium Challenge wargame, the US Department of Defense has developed much better capabilities to counter irregular and small unit tactics like those used by the Red team in that game,” he said. 

Nevertheless, “day-to-day US Navy ships could be at risk if attacked by a swarm of small boats during an ongoing confrontation or conflict,” he added. 

Even in that case, the US would deploy aircraft, including helicopter gunships like the AH-64 Apache and large heavily-armed Lockheed AC-130 ground-attack planes, to counter these small boats and defend civilian shipping. 

“The US military recently exercised these capabilities and would likely deploy them even during a period of heightened tensions with Iran,” Clark said. 

Furthermore, in any escalation with Iran, US aircraft carriers would not operate inside the Gulf but in the Arabian Sea, out of reach of those small IRGCN boats and where extra flying time would not significantly impact the number of sorties they could carry out over the Gulf. 

Unlike its adversarial relationship with the IRGCN, the US Navy coordinates and has “had a professional relationship” with the regular Iranian Navy in the Gulf. This, Clark noted, “is in part because of their similar structure and missions.” 

“The Iranian Navy operates larger ships and generally deploys to the Arabian Sea, Red Sea, and the Mediterranean, outside the Strait of Hormuz; the Iranian Navy conducts maritime security, surveillance, and training missions with Iran’s partners,” he said. 

The IRGCN, on the other hand, operates inside the Persian Gulf north of the Strait of Hormuz. 

Despite this relationship, the Iranian Navy would not necessarily avoid becoming involved in a confrontation with the US if tensions escalate. 

Chris Harmer, former Senior Naval Analyst at the Institute for the Study of War and a retired United States Naval Aviator who specializes in Iran’s maritime capabilities, notes that in the immediate aftermath of the 1979 Islamic Revolution, Iran’s regular conventional armed forces, known as the Artesh, remained loyal to the Shah. 

“The war with Iraq made it impossible for the Ayatollah to purge the Artesh military completely, so the IRGC was given the responsibility of guarding the regime against a counter-revolution led by the old guard military leadership,” Harmer told Rudaw English. 

While the Artesh was a “legitimate threat” to Iran’s Islamic regime 40 years ago, that threat has been largely reduced since the IRGC gained more power and remained the regime’s favored armed force. 

“Today, the IRGC so thoroughly dominates all sectors of Iranian society, including the military, it is difficult to envision a scenario where the IRGCN engaged in combat with the US Navy without the help of the Iranian Artesh Navy,” Harmer said. 

Consequently, while the US Navy and Iranian Navy maintain communications for deconfliction purposes, “there is no reason to assume the Iranian Artesh Navy would sit out a conflict with the US Navy.” 

While Harmer is confident the US Navy would “obliterate” both the IRGCN and Iranian Navy in any conflict, “that is not to say the Iranians could not inflict severe damage, especially if they launched a preemptive swarm attack with hundreds of small boats.” 

“While the US Navy has the ability to defend against small boat attacks, if even one suicide boat laden with explosives gets through, it could damage or sink a US Navy ship,” he said. 

However, the US still has some major advantages. Among them, Harmer notes, are its near-continuous surveillance of the area with satellites and unmanned aerial systems and its possession of long-range precision-guided munitions. 

“Tomahawk cruise missiles now have a range of 1,000 nautical miles and can be reprogrammed in flight,” he said. 

“If the US Navy were actually in a fight with the Iranian Navy, it would end with the total destruction of the Iranian Navy.”