By Kris Osborn, President, Center for Military Modernization
Iranian small boats have harassed and even interfered with US Navy ships, private commercial vessels and other platforms in the well-known and narrowly configured Strait of Hormuz, a scenario which has presented a persistent and difficult threat to shipping lanes and US national security concerns in the region.
Given this, the Pentagon’s decision to send a larger amount of US Navy assets to the region is by no means surprising as Iranian small boats have proven to be a credible and potentially lethal threat.
The tactical concept is to simply blanket or overwhelm a larger surface ship with multiple points and angles of attack so as to confuse and overwhelm deck-mounted guns and ship defenses. Explosive packed small boats or those armed with shoulder-fired missiles could be in position to exact a substantial toll on larger warships, while of course easily intimidating or interfering with commercial vessels.
The threat has been periodic, yet quite significant and lethal, often venturing beyond mere provocation into direct, overt hostility and offensive military interference. US Central Command reports that threatening Iranian boats have twice been deterred by the presence of US Navy warships. This is quite significant as, according to a Pentagon report, Iranian vessels actually “fired upon” a Bahamian-flagged oil tanker.
“The Bahamian-flagged oil tanker Richmond Voyager was approached by an Iranian naval vessel. That Iranian naval vessel got within one mile of the tanker and fired on it using small arms and crew-served weapons. As happened with the TRF Moss, the Iranian vessel left when the USS McFaul (destroyer) arrived on the scene,” a Pentagon report states.
These recent occurrences are by no means isolated instances, as Centcom reports that Iran has seized at least 20 vessels since 2021.
US Navy Ship Defenses
Why are the Iranian vessels taking off so quickly when US warships arrive? The answer may seem simple and self-evident given the firepower of Navy destroyers. However, small boats have shown an ability to present a significant military threat to large warships, a reason why the US Navy has in recent years taken specific and impactful measures to improve ship-defences. The service has conducted numerous live-fire drills and scenario reenactments to sharpen its ability to counter and destroy swarming small boat attacks. For example, most surface Navy warships operate with a ship-defense weapon referred to as Close-In-Weapons-System, or CWIS, a phalanx gun “area” weapon able to fire hundreds of small metal projectiles across a wide envelope in seconds to destroy incoming enemy missiles, aerial drone swarms and even lower flying helicopters or other fast-incoming attacks. However, roughly 10 years ago the Navy upgraded CWIS into what’s called a “1b” variant expanding its aperture from purely air-defense to counter-surface. The new 1B variant, which is now operational across Navy warships, specifically enables the fast-firing Phalanx area weapon to “blanket” incoming small boats across a wide “surface” area, essentially denying any ability for small boats to survive moving close in to large warships. A surface-firing CWIS, therefore, might be well positioned to stop, disable or simply destroy a large number of swarming small boats in a way other weapons could not.
Also, small short-and-mid range deck fired interceptors such as SeaRAM and Rolling Airframe Missile have been massively upgraded to increase range, lethality and precision, weapons enhancements increasingly capable of targeting and destroying fast-moving small boats. These weapons upgrades go back as far as 2015 when the Navy’s surface force implemented a fleet-wide “distributed lethality” program to massively arm the surface fleet with a new generation of more capable weaponry. The concept was to help the Navy transition from what was primarily a counter-terrorism role during the Iraq and Afghanistan wars into a “blue-water” and “open water” fighting force capable of destroying large, high-tech, great power warships.
US Navy Maritime Air Power
Finally, yet another critical factor is, quite simply, the air assets the Navy can deploy from amphibs and destroyers. Amphibious assault ships, such as the USS Bataan now in the region, can carry more than 24 rotary-wing and fixed wing attack aircraft, including the F-35B and MV-22 Osprey. Therefore, should US amphibs dispatch armed F-35Bs over the waters in the region, Iranian small boats would likely instantly be aware of their vulnerability. With its long-range, precision sensors and next-generation air-to-surface weaponry, a single F-35B would be positioned to obliterate groups of swarming small boats. Sensors on an F-35B, especially if networked with US Navy drones and other air and surface assets, could see and track Iranian small boats from substantial stand-off distances.
It also goes without saying that amphibious assault ships and dock landing ships such as those deployed in the Strait of Hormuz by CentCom present the threat of a sea-land amphibious assault beach landing supported by 5th-generation air power. Added to this threat is the reality that amphibious ships which typically operate as part of an Amphibious Ready Group or Marine Expeditionary Unit can perform highly-networked, disaggregated kinds of missions due to advanced networking technologies, enabling amphibs to deter Iranian forces across a much wider operational envelope.
Kris Osborn is the President of Warrior Maven – Center for Military Modernization. Osborn previously served at the Pentagon as a Highly Qualified Expert with the Office of the Assistant Secretary of the Army—Acquisition, Logistics & Technology. Osborn has also worked as an anchor and on-air military specialist at national TV networks. He has appeared as a guest military expert on Fox News, MSNBC, The Military Channel, and The History Channel. He also has a Masters Degree in Comparative Literature from Columbia University
