ROCKETS VS. MISSILES: Rockets are unguided, while missiles are guided surface-to-surface weapons systems that follow a parabolic flight path to their target. Rockets have solid fuel motors; missiles may have solid- or liquid-fuel motors. Ballistic missiles fall into several range classes:
- SRBMs: short-range ballistic missiles have a range of up to 1,000 km.
- MRBMs: medium-range ballistic missiles have a range of 1,000-3,000 km.
- IRBMs: intermediate-range ballistic missiles have a range of 3,000-5,500 km.
- ICBMs: intercontinental ballistic missiles have a minimum range of 5,500 km.
Cruise missiles are generally powered by air-breathing engines (turbojets or turbofans) and rely on small wings to create aerodynamic lift to stay aloft, flying at low altitudes to their target.
Liquid-fuel missiles operate under a number of constraints. Predeployment systems checks and fueling can take several hours, and launch site procedures for mobile systems can take an additional hour, during which time the missiles are vulnerable to detection and interdiction. They are also more likely to incur damage en route to the launch site when they have been already fueled-due to the stress the filled fuel and oxidizer tanks place on the missile fuselage-increasing the risk of a catastrophic failure upon launch. After fueling, however, they can be kept in a state of readiness for months. Solid fuel missiles, by contrast, offer greater responsiveness and operational flexibility, as they are nearly always ready for use, can better endure cross-country movements, and can be launched from presurveyed launch sites or silos on short notice-often within minutes.
ACCURACY AND PAYLOAD:
Missile accuracy is measured in terms of circular error probable (CEP), the radius of a circle within which 50 percent of missiles aimed at its center will land. The CEPs of Iran’s missiles are believed to vary widely, from 100 meters for short-range systems like the Fateh-110 and its derivatives and perhaps the longer-range Emad, to several hundred meters for the Shahab-1 and 2, the Qiam, and the Ghadr, to 1 km or more for the Shahab-3. Moreover, missiles can deliver relatively limited payloads-from around 500 kg for some models of the Fateh-110 to 1,000 kg for the Shahab-3. By contrast, a single modern strike aircraft can carry thousands of kilograms of bombs and deliver them within meters of the target.
Studies have estimated that it could take large numbers of highly accurate short-range missiles (e. g., Fateh-110s) and massive numbers of less accurate long-range missiles (e. g., Shahab-3s) to destroy even a single oil-production facility or export terminal in the Gulf. Even inaccurate missile salvos, however, could disrupt operations at these facilities and do some damage, though systems redundancies and excess capacity would ensure that the effects of such attacks on oil exports would likely be short-lived. Likewise, Iran’s missile force is believed to lack the accuracy and numbers needed to target military air bases in a way that would significantly disrupt U. S. and coalition air operations in the region.
The Gulf probably has scores of civilian and military targets like these, and attrition imposed by coalition missile defenses would further dampen the impact of Iranian missile strikes. That is why Iran’s less accurate long-range missiles are likely to be launched against population centers in wartime. However, significant improvements to the accuracy of its missiles would be a game changer for Tehran, which is probably why it is devoting much effort to achieving this goal.
WARHEADS:
Missile warheads come in a variety of types: nonseparating or separating, conventional or nonconventional, and unitary or cluster:
NONSEPARATING/SEPARATING: Nonseparating warheads remain joined to the missile’s fuselage during flight and through impact. Missiles with nonseparating warheads are simpler to produce, but may become unstable during descent and tumble, resulting in diminished accuracy. The airframe and warhead may also present a larger and slower-hence more vulnerable-target to missile defenses than separating warheads.
CONVENTIONAL/NONCONVENTIONAL: Conventional warheads carry high-explosive (HE) payloads, whereas nonconventional warheads may carry chemical, biological, or nuclear payloads.
UNITARY/CLUSTER: Unitary warheads carrying bulk HE or chemical/biological warfare (CBW) agent payloads explode upon impact or at a predetermined altitude. Cluster munitions warheads carry their explosive or CBW agent payload in numerous unguided bomblets and disperse them over the target at a predetermined altitude.
Cluster warheads should not be confused with the much more sophisticated MIRVs (multiple independently targetable reentry vehicles), which were developed by the superpowers during the Cold War to enable a single missile to deliver several nuclear weapons against multiple targets.
BASING AND LAUNCH MODES: Basing and launch modes can include: fixed aboveground launch sites; mobile transporter-erector launchers (TELs); conventional silos; underground launch complexes; and railway launchers.
FIXED ABOVEGROUND LAUNCH SITES: Usually located near missile storage bunkers or depots so that the missiles can be rapidly assembled, fueled, erected on a launchpad, and launched. Fixed aboveground sites, however, are vulnerable to detection. During World War II, Germany used hastily established aboveground launch sites for its V-2 missiles, and built several hardened aboveground launch complexes that were never completed. Iraq built several fixed aboveground launch sites in western Iraq prior to the 1991 Gulf War but never used them. There is no evidence that Iran uses fixed aboveground launch sites, except for missile test launches.
MOBILE TELs: Kept in underground or mountainside bunkers or camouflaged hide sites until needed. At that time, missiles are fueled (if they have not been fueled already) and transported on the TELs to presurveyed launch sites, where they are erected and launched. The mobility of TELs, many of which can move both on- and off-road, combined with camouflage and deception measures (e. g., disguising the TEL and support vehicles as civilian trucks, as done by Iran, enhances their survivability. Russia, China, and North Korea all deploy road-mobile launchers for their strategic missile forces.
CONVENTIONAL SILOS: Located underground, constructed of concrete and steel, and protected by overhead blast doors. Iran’s austere conventional silos would seem to require a missile to be lowered inside by a crane, where it would then be fueled. A fueled missile could stay on alert for several months, as long as the fuel remained viable. Iran’s missile silos seem to be onetime-use installations, though the need to emplace missiles from aboveground increases the likelihood of detection prior to use. The United States and Russia have deployed large numbers of strategic missiles in these types of silos since the 1960s.
UNDERGROUND LAUNCH COMPLEXES: Usually located under a mountain. Iran has released videos of one or more of these missile bases. Missiles are kept on ready racks and transported by truck via tunnels to underground missile halls, where they are fueled, erected, and launched through a small aperture in the ceiling. They may also be fueled and then transported on TELs via entry/exit portals to nearby presurveyed aboveground launch sites, employing “surface and shoot” tactics. Underground missile bases can be hard to locate, and thus make it difficult to detect launch preparations or to attack the missiles and their support infrastructure prior to launch. China is believed to operate an extensive network of underground tunnels for its road-mobile strategic missile forces.
RAILWAY LAUNCHERS: Usually consist of a horizontal, coffin-type container on a railcar. Iran has shown a brief film clip of a railcar-based Shahab-type missile with a sliding overhead door. The missile would be transported by rail to a predesignated launch site, where it would be erected and launched from the railcar. While this option would enable Iran to hide its mobile railcar launchers among its civilian railway traffic, the launcher would be limited to areas served by rail lines. It is not known whether this is an operational Iranian capability. The Soviet Union deployed missiles on railcars in the late 1980s, and Russia is reportedly considering reviving this capability. China has reportedly tested a railcar-based missile for future deployment. And the United States investigated the use of railcars for its strategic missile forces but never adopted this basing mode.
Iran may have also considered the possibility of launching missiles from merchant ships at sea, and reportedly test-launched a short-range missile from a barge in the Caspian Sea in 1998. This option could greatly expand the reach of Iran’s missile force, allowing it to target the United States before it developed an operational ICBM. However, beyond the single reported missile test, it is not clear that Iran has done more to acquire such a capability.
The semi-official Fars news agency, believed to be close to the Guard, identified the six missiles used as Zulfiqar and Qiam variants, which have ranges of 750 km (465 miles) and 800 km (500 miles) respectively.
Iran also launched drone attacks on the site afterward, state TV reported.
The Qiam-1, which means ‘Uprising’ in English, is a surface-to-surface ballistic missile developed by Iran under its weapons program started in 1992 as a response to the United States arms embargo. It is fueled by liquid propellant and has an improved accuracy compared to its predecessors developed in Iran. The Qiam-1 missile has no wings which makes it faster, harder to detect and track, and thus more difficult to intercept. The Iranian Ministry of Defense (MoD) announced that the Qiam-1 was first test launched successfully on August 20, 2010. The MoD also claims that the missile is a breakthrough in terms of missile technology developed in Iran. The Iran’s military took delivery of the first production Qiam-1, also referred to as Qiyam-1, on May 22, 2011.
Iran’s missile force could double or triple in size by the time the major limits imposed by the nuclear deal are lifted, fifteen years from now. By then, Iran’s growing missile and cyber capabilities will pose major challenges to regional missile defenses, military and critical infrastructure targets, and civilian population centers. This would make preventive action by Israel or the United States, in the event of an attempted Iranian nuclear breakout, much more costly.
Finally, an Iranian nuclear missile force would be highly destabilizing. Short missile flight times between Iran and Israel, the lack of reliable crisis communication channels, and the impossibility of knowing whether incoming Iranian missiles are conventional or nuclear could someday spur Israel-and any other regional nuclear states that emerge in the interim-to adopt a launch-on-warning posture, undermining the prospects for a stable nuclear deterrent balance in the region.
Iran has a large, diverse, highly capable missile force consisting of very accurate shortrange solid fuel missiles, more than 1,000 less accurate but longer-range liquid-fuel Shahab-type missiles, and an unknown number of land-attack cruise missiles. Its short-range ballistic missiles (SRBMs) are for use against near enemies in the Gulf and include the Fateh-110 (with a claimed range of 300 km), Shahab-1 (300 km), Shahab-2 (500 km), Fateh-313 (500 km), Zulfiqar (700 km), and Qiam (800 km). Its medium-range ballistic missiles (MRBMs) are for use against Israel and include the Shahab-3 (1,000 km), Ghadr (1,600 km), and Emad (1,700 km).These are believed to be conventionally armed with unitary high-explosive or submunition (cluster) warheads. The aforementioned MRBMs have sufficient excess range to be launched against Israel and the Gulf states from the heart of Iran, where they would be less vulnerable to preemption, and some may have the ability to fly depressed or lofted trajectories, thereby complicating the task of missile defenses.
Iran has also tested a two-stage solid fuel missile, the Sejjil-2, whose range of over 2,000 km would allow it to target southeastern Europe-though it is apparently still not operational. In June 2011, IRGC Aerospace Force commander Brig. Gen. Amir Ali Hajizadeh announced that Iran was capping the range of its missiles at 2,000 km (sufficient to reach Israel but not Western Europe). He stated that “there is no threat from any country to us other than the U. S. and the Zionist regime” and that “the range of our missiles has been designed on the basis of the distance to the Zionist regime and the U. S. bases in the Persian Gulf region.” He added that while Iran “possesses the technology… we have no intention to produce such missiles,” implicitly eschewing the development of intercontinental ballistic missiles (ICBMs) in a presumed bid to deflect U. S. and European concerns. However, Iranian defense minister Brig. Gen. Hossein Dehqan stated in August 2016 that “we don’t have any limit for the range of liquid- or solid-fuel ballistic missiles,” apparently indicating the lifting of the previous self-imposed limit. Accordingly, Iran is reported to have recently tested, unsuccessfully, a version of the North Korean BM-25 Musudan intermediate-range ballistic missile (IRBM), with an estimated range of 4,000 km. This missile would enable Iran to hit the heart of Western Europe.
Iran’s Safir space launch vehicle (SLV), which has put four satellites into orbit since 2009, could provide the experience and know-how needed to build an ICBM. Some assessments suggest that the Safir struggled to put a very small satellite into low-earth orbit and has therefore probably reached the outer limits o its performance envelope-and could not serve as an ICBM. In 2010, Iran displayed a full-size mockup o a larger two-stage SLV, the Simorgh, which it first tested in April 2016. It would seem that Iran is keeping its options open for developing an ICBM. Indeed, U. S intelligence reports indicate that Iran and North Korea are collaborating on the development of a large rocket motor suitable for use in an SLV or ICBM-which may have been the engine tested by North Korea in September 2016.
