An anti-ship missile (AShM or ASM) is a guided missile that is designed for use against ships and large boats. Most anti-ship missiles are of the sea-skimming variety, and many use a combination of inertial guidance and active radar homing. A large number of other anti-ship missiles use infrared homing to follow the heat that is emitted by a ship; it is also possible for anti-ship missiles to be guided by radio command all the way. Many anti-ship missiles can be launched from a variety of weapons systems including surface warships (also referred to as ship-to-ship missiles), submarines, bombers, fighter planes, patrol planes, helicopters, shore batteries, land vehicles, and, conceivably, even infantrymen firing shoulder-launched missiles. The term surface-to-surface missile (SSM) is used when appropriate. The longer-range anti-ship missiles are often called anti-ship cruise missiles. Several countries are also developed Anti-ship ballistic missiles.

Etymology

Both "AShM" and “ASM” are utilized interchangeably as an acronym for "anti-ship missile." "AShM" may be the preferred acronym when confusion with "air-to-surface missile" (commonly abbreviated as "ASM") may occur.

History

During the Cold War, the Soviet Union turned to a sea-denial strategy concentrating on submarines, naval mines and the AShM. One of the first products of the decision was the SS-N-2 Styx missile. Further products were to follow, and they were soon loaded onto the Soviet Air Force's Tu-95 Bear and Tu-22 Blinder bombers, in the case of the air-launched KS-1 Komet. In 1967, the Israeli Navy's destroyer INS Eilat (1955) was the first ship to be sunk by a ship-launched missile—a number of Styx missiles launched by Egyptian Komar-class missile boats off the Sinai Peninsula. In the Indo-Pakistani War of 1971 the Indian Navy conducted two raids using Osa-class missile boats employing the Styx on the Pakistani naval base at Karachi. These raids resulted in the destruction or crippling of approximately two thirds of the Pakistani Navy. Major losses included two destroyers, a fleet oiler, an ammunition ship, approximately a dozen merchant ships, and numerous smaller craft. Major shore-based facilities, including fuel storage tanks and naval installations were also destroyed. The Osas returned to base without loss. The Battle of Latakia in 1973 (during the Yom Kippur/Ramadan War) was the scene of the world's first combat between missile boats. In this battle, the Israeli Navy destroyed Syrian warships without suffering any damage, using electronic countermeasures and ruses for defense. After defeating the Syrian Navy the Israeli missile boats also sank a number of Egyptian warships, again without suffering any damage in return, thus achieving total naval supremacy for the rest of the war. Anti-ship missiles were used in the 1982 Falklands War. The British warship HMS Sheffield (D80), a Type 42 destroyer, was struck by a single air-launched Exocet and later sank as a result of the damage. The container ship Atlantic Conveyor was hit by two Exocets and burnt out and subsequently sank while under tow. HMS Glamorgan (D19) was damaged when she was struck by an MM38, a ship-launched version of the Exocet, fired from a launcher taken from the Argentine Navy destroyer ARA Comodoro Seguí and mounted on a trailer by Navy technicians, but she had taken evasive action that limited the damage. In 1987, a US Navy guided-missile frigate, USS Stark (FFG-31), was hit by an Exocet anti-ship missile fired by an Iraqi Mirage F-1 fighter plane. Stark was damaged, but she was able to steam to a friendly port for temporary repairs. In October 1987, Sungari, an American-owned tanker steaming under the Liberian flag, and MV Sea Isle City, a Kuwaiti tanker steaming under the American flag, were hit by Iranian HY-2 missiles. In 1988 AShMs were fired by both American and Iranian forces in Operation Praying Mantis in the Persian Gulf. During this naval battle, several Iranian warships were hit by American AShMs (and by the US Navy's Standard missiles—surface-to-air missiles which were doing double-duty in the anti-ship role). The US Navy hit the Iranian Navy frigate Sahand with three Harpoon missiles, four AGM-123 Skipper rocket-propelled bombs, a Walleye TV-guided bomb, and several 1,000 lb "iron bombs". Despite the large number of munitions and successful hits, Sahand did not sink until fire reached her ammunition magazine, causing it to detonate, sinking the vessel. In the same engagement, American warships fired three Standard missiles at an Iranian Navy corvette. This corvette had such a low profile above the water that a Harpoon missile that arrived several minutes later could not lock onto it with its targeting radars. In 2006, Lebanese Hezbollah fighters fired an AShM at the Israeli corvette INS Hanit, inflicting battle damage, but this warship managed to return to Israel in one piece and under its own power. A second missile in this same salvo struck and sank an Egyptian merchant ship. On 13 April 2022, the Ukrainian government claimed to have hit the Russian cruiser Moskva with two R-360 Neptune missiles, resulting in its sinking. The Russian government did not confirm the attack, but admitted that the ship sank after a fire. If Ukrainian claims are true, Moskva might be the largest warship ever disabled or destroyed by a missile, according to Carl Schuster, a retired US Navy captain and former director of operations at the US Pacific Command's Joint Intelligence Center.

Threat posed

Anti-ship missiles are a significant threat to surface ships, which have large radar, radio, and thermal signatures that are difficult to suppress. Once acquired, a ship cannot outrun or out-turn a missile, the warhead of which can inflict significant damage. To counter the threat posed, the modern surface combatant has to either avoid being detected, destroy the missile launch platform before it fires its missiles, or decoy or destroy all of the incoming missiles. Modern navies have spent much time and effort developing counters to the threat of anti-ship missiles since the Second World War. Anti-ship missiles have been the driving force behind many aspects of modern ship design, especially in navies that operate aircraft carriers. The first layer of antimissile defense by a modern, fully equipped aircraft carrier task force is always the long-range missile-carrying fighter planes of the aircraft carrier itself. Several fighters are kept on combat air patrol (CAP) 24 hours a day, seven days a week when at sea, and many more are put aloft when the situation warrants, such as during wartime or when a threat to the task force is detected. These fighters patrol up to hundreds of miles away from the task force and they are equipped with airborne radar systems. When spotting an approaching aircraft on a threatening flight profile, it is the responsibility of the CAP to intercept it before any missile is launched. If this cannot be achieved in time, the missiles themselves can be targeted by the fighters's own weapons systems, usually their air-to-air missiles, but in extremis, by their rapid-fire cannon. However, some AShMs might "leak" past the task force's fighter defenses. In addition, many modern warships operate independently of carrier-based air protection and they must provide their own defenses against missiles and aircraft. Under these circumstances, the ships themselves must utilize multilayered defenses which have been built into them. For example, some warships, such as the US Navy's Ticonderoga-class cruiser guided missile cruisers, the Arleigh Burke-class destroyer guided missile destroyers, and the Royal Navy's Type 45 guided missile destroyer, use a combination of radar systems, integrated computer fire-control systems, and agile surface-to-air missiles (SAM) to simultaneously track, engage, and destroy several incoming anti-ship missiles or hostile warplanes at a time. The primary American defensive system, called the Aegis Combat System, is also used by the navies of Japan, Spain, Norway, South Korea, and Australia. The Aegis system has been designed to defend against mass attacks by hostile anti-ship missiles or warplanes. Any missiles that can elude the interception by medium-ranges SAM missiles can then be either deceived with electronic countermeasures or decoys; shot down by short-range missiles such as the Sea Sparrow or the Rolling Airframe Missile (RAM); engaged by the warship's main gun armament (if present); or, as a last resort, destroyed by a close-in weapon system (CIWS), such as the American Phalanx CIWS, Russian Kashtan CIWS, or the Dutch Goalkeeper CIWS.

Current threats and vulnerabilities

To counter these defense systems, countries such as Russia are developing or deploying missiles that slowly cruise at a very low level (about five meters above sea level) to within a short range of their target and then, at the point when radar detection becomes inevitable, initiate a supersonic, high-agility sprint (potentially with anti-aircraft missile detection and evasion) to close the terminal distance. Missiles, such as the SS-N-27 Sizzler, that incorporate this sort of threat modality are regarded by US Navy analysts as potentially being able to penetrate the US Navy's defensive systems. Recent years have seen a growing amount of attention being paid to the possibility of ballistic missiles being re-purposed or designed for an anti-ship role. Speculation has focused on the development of such missiles for use by China's People's Liberation Army Navy. Such an anti-ship ballistic missile would approach its target extremely rapidly, making it very difficult to intercept. In response to China's development of anti-ship missiles and other anti-access/area denial capabilities, the United States has developed the AirSea Battle doctrine.

Countermeasures and defenses

Countermeasures against anti-ship missiles include Ships that employ some stealth technology can reduce the risk of detection and make themselves a harder target for the missile through the use of passive countermeasures including:

History of combat interceptions

Gulf War

On February 25, 1991, during the first Gulf War, the Phalanx-equipped USS Jarrett (FFG-33) was a few miles from USS Missouri (BB-63) and the destroyer HMS Gloucester (D96). The ships were attacked by an Iraqi Silkworm missile (often referred to as the Seersucker), at which Missouri fired its SRBOC chaff. The Phalanx system on Jarrett, operating in the automatic target-acquisition mode, fixed upon Missouri's chaff, releasing a burst of rounds. From this burst, four rounds hit Missouri which was 2 to 3 mi from Jarrett at the time. There were no injuries. A Sea Dart missile was then launched from HMS Gloucester, which destroyed the Iraqi missile, achieving the first successful engagement of a missile by a missile during combat at sea.

2016 attacks off the coast of Yemen

On 9 October 2016, USS Mason (DDG-87), operating near the Bab-el-Mandeb strait, was targeted by two missiles fired from Houthi-controlled territory. Both missiles fell short and crashed into the water. The Houthi insurgency denied launching the attack on the warship. The United States Naval Institute reported that Mason fired two SM-2 Standard missiles and one RIM-162 ESSM missile to intercept the two missiles, and deployed her Nulka missile decoy. One of two U.S. defense officials cited anonymously added that it was not clear whether the incoming missiles had been shot down or crashed into the water on their own. This marked the first recorded instance of ship-based anti-air missiles being fired from vertical launching cells in combat in response to an actual inbound missile threat. On 12 October 2016 USS Mason (DDG-87) was again targeted by missiles fired from Yemeni territory, while it was operating in the Bab el-Mandeb strait. Mason was not hit by the two missiles, which were fired from near the southern Yemen city of Al Hudaydah. While the Navy was not certain whether the first incoming missile was intercepted or instead just fell into the sea, officials said Mason successfully intercepted the second missile at a distance of about 8 mi, marking the first time in history a warship destroyed an inbound anti-ship missile with a SAM in actual self-defense. On 13 October 2016, the U.S. attacked three radar sites in Houthi-held territory which had been involved in the earlier missile attacks, with cruise missiles launched from Nitze. The Pentagon assessed that all three sites were destroyed. On 15 October 2016, USS Mason (DDG-87) was targeted in a third attack by Houthi rebels based in Yemen, by five anti-ship cruise missiles while operating in the Red Sea north of the Bab el-Mandeb strait. Mason fired a radar decoy, an infrared decoy, and several SM-2 Standard missiles in response, either neutralizing or intercepting four of the five incoming missiles. The Navy reported the fifth incoming missile as neutralized by a radar decoy launched from Nitze, after Mason alerted her to the threat.

2023 Houthi missile attacks

On 26 December 2023, the USS Laboon shot down three ASBMs in the Red Sea fired by Houthi rebels with multiple SM-6s. This was its first intercept of a ballistic missile in combat. On 30 December 2023, Danish container ship Maersk Hangzhou issued a distress call after coming under fire from four small ships commanded by Iranian-backed Houthi rebels from Yemen. Attempts were also made to board Maersk Hangzhou by force, while a contracted security team defended the ship. USS Gravely (DDG-107) and aircraft carrier USS Dwight D. Eisenhower (CVN-69) responded to a distress call from the container ship. Verbal commands were radioed to the Houthi ships, while helicopters from Eisenhower were dispatched. After taking small arms fire, U.S. Navy helicopters returned fire, sinking three of the four Houthi ships. There was no damage to U.S. equipment or personnel. In the process of responding to the distress call, Gravely shot down two anti-ship ballistic missiles fired from Yemen. On Jan. 9, at approximately 9:15 p.m. (Sanaa time), Iranian-backed Houthis launched a complex attack of Iranian designed one-way attack UAVs (OWA UAVs), anti-ship cruise missiles, and an anti-ship ballistic missile from Houthi-controlled areas of Yemen into the Southern Red Sea, towards international shipping lanes where dozens of merchant vessels were transiting. Eighteen OWA UAVs, two anti-ship cruise missiles, and one anti-ship ballistic missile were shot down by a combined effort of F/A-18s from USS Dwight D. Eisenhower (CVN-69), USS Gravely (DDG-107), USS Laboon (DDG 58), USS USS Mason (DDG-87), and the United Kingdom’s HMS Diamond. This is the 26th Houthi attack on commercial shipping lanes in the Red Sea since Nov. 19. There were no injuries or damage reported. On 14 January 2024, an anti-ship missile was fired in the direction of Laboon from a Houthi-controlled portion of Yemen, according to CENTCOM. Two weeks later, on 30 January 2024, the USS Carney shot down an ASBM in the Gulf of Aden fired by Houthi rebels with an SM-6. On 30 January 2024, USS Gravely used its Phalanx CIWS to shoot down an incoming anti-ship cruise missile fired by the Houthis. U.S. officials said that the missile came within a mile of the destroyer. No damage or injuries were reported. On February 6, 2024 at 4:30 p.m., while patrolling in the Gulf of Aden, USS Laboon (DDG 58), operating near M/V Star Nasia, intercepted and shot down an anti-ship ballistic missile fired by the Iranian-backed Houthis. Later in the month, on 20 February 2024 at 12:30 a.m., while operating in the Gulf of Aden, Laboon detected and shot down one anti-ship cruise missile fired by the Houthis.

Comparison