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Saeqeh / Ahoya / AHWA
HY-2 C201 Silkworm/Seersucker

The nomenclature of this missile in Iranian service is a bit confusing. Western accounts reference the Silkworm missile, which in Chinese service was the HY-1. But the missile exported to Iran was the HY-2 / C201, known in the West as the SEERSUCKER or SAFFLOWER, depending on the launch mode. China may have exported the related HY-4 SADSACK C-201W/C-601. All are lumped together in public accounts as Silkworms. Iranian nomenclature is a bit of a puzzle, as their designation for the initial batch of missiles is poorly attested. They may have simply been called Ahoya / Achuay / Achuya / AHWA = Silkworm, although the system eventually acquired the nomenclature Saeqeh (Persian = "thunderbolt") [the Iranian version of the F-5, is known locally as the Saeqeh, ]. More recently upgraded variants are known as Ra'ad = Thunderbolt.

In the Western world, the discussion of anti-ship cruise missiles was not taken seriously, and most Western countries believed that large-scale naval operations and aircraft carriers would be enough to fight at sea. All these ideas changed on October 21, 1967. On this day, Israeli destroyer Eilat was hit by two SS-N-2 missiles fired from an Egyptian Osa-class missile boat, killing 47 Israeli sailors. The attack was the first successful use of the anti-ship cruise missiles in the battle, and forever changed the battle scene of the sea. In 1971, the missile flashed once again during the Indian-Pakistani naval battle and successfully hit several Pakistani flotilla targets.

Iran had obtained Silkworm missiles from the People’s Republic of China as early as September of 1986. The Silkworm is an anti-ship missile with a range of fifty miles and a warhead containing three times the power of an Exocet warhead. Coastal defense cruise missiles (CDCMs) are an important layer in Iran’s defense of the Persian Gulf and Strait of Hormuz. Iran can attack targeted ships with anti-ship cruise missiles (ASCMs) from its own shores, islands, and oil platforms using relatively small mobile launchers.

The C801/802 is Iran’s primary CDCM, first imported from China in 1995. It is capable of engaging targets at a range of six nautical miles, and has greater accuracy, a lower cruising altitude, and a faster set-up time than the Seersucker missile Iran used during the Iran-Iraq War. The C801/802 allows Iran to target any point within the Strait of Hormuz and much of the Persian Gulf and the Gulf of Oman. Iran has worked with China to develop shorter range missiles, including the C701, for deployment in narrow geographic environments.

Iran can readily deploy its mobile CDCM launchers anywhere along its coast. These systems have auto control and radar homing guidance systems, and some can target using a remote air link. Iran’s objective is to overwhelm enemy air defenses with mobile CDCMs, combined with multiple rocket launchers (MRLs), coastal artillery, and ballistic missiles. Mobile CDCMs, combined with multiple rocket launchers (MRLs), coastal artillery, and ballistic missiles, Iran hoped to overwhelm enemy air defenses.

Tehran became interested in acquiring the Chinese-made Silkworm antiship missile after Iranian military and political officials visited Beijing in the late summer of 1985 . Despite Iranian reservations about the quality of the weapon, the Revolutionary Guard signed a contract later that year to purchase several hundred Silkworm missiles and 48 launchers (12 batteries of 4 launchers each). Both the Revolutionary Guard and the Iranian Navy were to receive the missiles.

The Iranians intended to use the missiles to counter new frigates that Italy was building for Iraq and that were scheduled for delivery in 1986. B July 1987 four launcher vehicles, 20 missile crates, and the related radar and support vehicles had been seen during unloading operations at the port. Tehran may have received additional missiles and launchers. The remainder of the Silkworm launchers and missiles specified in the contract arrived in Iran later in the year. At that time, US intelligence had identified at least four possible prepared Silkworm launch sites - two on Qeshm Island and two at Kuhestak - near the Stiait of Hormuz.

CIA believed Tehran viewed the Silkworm as giving substance to its claim that Iran had a sophisticated weapon that can sink ships. In many ways the Silkworm combined the range, destructive power, and expendability lacking in other Iranian antiship weapons. These capabilities supported Iran's overall strategy of attacking tankers to coerce the Gulf states into reducing their political and economic support for Iraq and to weaken the Gulf states' support for increased American presence in the Gulf. Tehran probably also hoped that the threat posed by the missile against US warships will intensify debate in Washington, eventually forcing the United States to withdraw its naval presence from the Gulf.

The Silkworm's 1,100 pound high-explosive warhead is likely to seriously damage or sink warships or tankers. It has an armor-piercing capability and is over three times the weight of the Exocet warhead that severely damaged the USS Stark. In the 1967 Arab-Israeli war, Egypt sank an Israeli destroyer with two missiles similar to the Silkworm. The US estimated that one Silkworm could cause sufficient hull damage or fires to sink even the largest supertanker. The missile was assessed as having a 50 to 70 percent chance of hitting a larger ship that is not protected by passive or active countermeasures.

I CIA believed the chance of an unauthorized firinq of a Silkworm was low. Iran's Navy probably would be less zealous than the Guard in its willingness to fire a Silkworm, especially against a US ship. Nonetheless, if ordered, the Naval units would launch the missile. The religious fervor and anti-US sentiments of the Revolutionary Guard made it more dangerous, but there was little evidence that the Guard undertakes unauthorized activities. Instead, the evidence suggests that the Guard has been brought more closely under the control of the central government in the 1980s. Some analyts in the intelligence community, while recogn1z1ng the institutionalization of the Guard, cannot entirely discount the possibility that a local Guard commander might act independently to attack a US-flag ship, especially if hostilities already were underway. Although Navy personnel probably are more technically competent than Revolutionary Guards, both services are capable of firing the Silkworm. The Revolutionary Guard's lack of educated personnel and difficulty operating technical systems in the past suggest that the Guard was more likely to make mistakes that would reduce the effectiveness of the Silkworm.

Iranian leaders were unlikely to give any public indication that they are preparing to use the Silkworm. Instead, their public statements probably would remain ambigious to hide their intentions and allow them to justify and carry out a variety of actions. Statements by US officials concerning possible preemptive strikes would make Tehran especially careful not to give any sign that it is preparing to use the missiles.

Little or no tactical warning would be evident that a Silkworm missile was being prepared for launch. On the basis of statements of Iranian officials, Tehran was aware of Western intelligence efforts and would take precautions to hide the Silkworms and preparations for launch. The wheeled launcher can be moved and launched from any flat area along the coast. Prepared positions - such as the two sites near the Strait of Hormuz - are not needed for a launch.

Although Iran is most likely to fire a Silkworm from sites on or near the Iranian mainland, Tehran may try to use other locations to surprise or reduce warning to targets and extend the Silkworm's capabilities. Iran could, for example, put a Silkworm launcher and launch equipment onto a large barge or ship to carry out shipping attacks from unexpected directions anywhere in the Gulf. Launching a Silkworm from a ship would reduce the effectiveness of the missile, but it still would have a considerable chance of hitting a target. Tehran might deploy missile launchers and radars to Farsi Island, in the central Gulf, from which Silkworms would have the range to hit any ship attempting to reach Kuwait The Iranians also could place a Silkworm launcher on one of their large offshore oil platforms in the Gulf.

The the Silkworm threat would be difficult to eliminate with air or naval attacks on Iran. Because of the unlikelihood that all the launchers and associated equipment would be found, a single or even repeated strikes probably would not destroy and might not even significantly reduce Iran's capability to attack ships with Silkworms. Tehran may have dispersed the Silkworms throughout the Bandar-e Abbas area - and perhaps other parts of Iran - to reduce the chance that all missiles could be destroyed in a preemptive attack. Even if the location of a launcher were known - for example after a launch - the Iranians would need less than two hours to dismantle a launcher and might be able to move it before an effective air or naval attack could be launched.

The Silkworm initially seemed to Western observers to be the least likely option Iran would use in the range of options it had to attack shipping in the Gulf. The Silkworm's high potential to heavily damage or sink a ship and its inability to strike specific targets among a group of ships made the Iranians reluctant to use it before they tried other measures. Among its other options, Iran could increase its mining of sea lanes because such activities would allow Tehran to deny responsibility and thus reduce the likelihood of us retaliation.

Iran might try to use small, maneuverable speed boats armed with light weapons in quick harassing raids on ships. If such measures failed to influence US activities, Tehran might consider attacks by small civilian aircraft, fighter aircraft, or Iranian warships. If backed into a corner, Iran's initial use of a Silkworm would be against a commercial ship or, should it occur, an unescorted US flag tanker traveling to or from Kuwait. Tehran might decide to strike a non-US tanker to demonstrate the Silkworm's capabilities and Iran's resolve while avoiding a direct attack on us ships. If the Iranians decide to attack escorted ships, they might prefer to use the Silkworm against tankers rather than the nearby US warship escorts. The Silkworm's poor target discrimination capability, however, increased the likelihood that an escort warship might be struck. Iran probably would deliberately target Silkworms against US warships only after a US air or naval attack on Iranian territory. The Iranian Revolutionary Guard hit the Sea Isle City tanker located in Kuwait’s Shuaiba oil loading terminal with a Silkworm anti-ship missile.

One of the conflict’s most debated topics involved whether Iran fired Silkworm missiles at U.S. Navy warships during Operation Praying Mantis on April 18, 1987. On several occasions the U.S. administration stated it would retaliate with strikes to missile launch sites in Iranian territory if Iran used Silkworms against U.S. ships. Despite significant evidence from U.S. Navy assets in the Gulf that Iran used Silkworms, Pentagon and Central Command officials denied the missile launches occurred. The United States withheld judgment regarding Iran’s use of Silkworms during Operation Praying Mantis in order to avoid an escalation in hostilities.

Akin to President Obama’s predicament over his August 2012 statement to reporters about a “red line” on Syria’s use of chemical weapons, the Reagan administration found itself in a similar situation over statements it made about a U.S. response if Iran used Silkworm missiles against U.S. Navy warships. One theory is that the U.S. had gotten itself into a box on the Iranian use of Silkworm missiles and chose to deny the event in order to prevent an escalation in hostilities that the United States was not politically ready to pursue.

There was compelling evidence of Iran’s Silkworm use, such as multiple U.S. Navy ships identifying the missiles with Electronic Warfare Support Measures, a Navy EA-6B aircraft visually identifying a Silkworm, and Iran’s likely motivation to use the Silkworm during a desperate attempt to strike back at the United States. A DoD Gulf Media Pool Report from the USS Jack Williams to reveal how Navy crew members had not only electronically detected incoming Silkworm missiles in the Persian Gulf on April 18, 1988, but had also visually identified them. The media pool system, used by the DoD in the late 1980s, involved allowing preselected groups of journalists to accompany DoD military forces during military operations.

In 1986, Kuwait asked the US to reregister 11 tankers--half of its fleet--under the American flag so they would be entitled to U.S. Navy protection against Iranian attack. On 04 September 1987 an Iranian Silkworm missile struck the coast of Kuwait in the first known use of the Chinese-made missiles during the Persian Gulf crisis. An Iranian Silkworm missile 16 October 1987 hit a U.S.-flagged oil tanker in Kuwaiti waters, injuring 18 crewmen. Iran did not openly claim responsibility for the attack. President Ali Khamenei told a laughing crowd at a prayer session in Teheran that, "Where the missile came from, only the Almighty knows." In retaliation, U.S. warships 19 October 1987 bombarded an offshore Iranian oil rig that was being used as a base for Iranian gunboats. Iran responded in turn 22 October 1987 by firing another missile into Kuwait's main offshore oil loading platform.

Iraqi forces forces used SS-N-2 (P-15 Termit) launched from Tu-22, French-made Exocet launched from Mirage F1 & Super Etendard and Chinese-made Silkworm as well as C-601 launched from Tu-16 and H-6 bombers, bought from the Soviet Union and China to engage the Iranian Navy and tankers carrying Iranian oil.

In March 1988, China agreed to stop supplying Iran with HY-2 missiles, though it reportedly supplied Iran until 1989. Iran since developed the capability to manufacture these missiles itself.

In July 2006, during the month-long war between Israel and Hezbollah in Lebanon, when an Israeli warship, the INS Hanit, was hit and disabled by an Iranian variant of the Silkworm or Saccade — a missile that Israeli officials previously did not know the Shi’ite militia possessed.

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Page last modified: 18-07-2019 16:02:13 ZULU