While the legacy of the Reagan administration’s Strategic Defense Initiative (SDI) may have initially put the US ahead in directed energy-based missile defense capabilities, Israel, Russia and China have started to deploy and accelerate the development of similar systems in response to new missile threats and the mixed success at best of traditional missile defense platforms.
There are basic principles of physics that make laser or other directed energy-based missile defense systems superior by potentially orders of magnitude to “shooting down bullets with bullets”, as most prevailing systems aim to do.
Iraqi missile attacks during the 1991 Gulf War, Iran’s expanding missile arsenal and the failure of Israeli airstrikes to destroy Hezbollah’s missile launchers during the 2006 Lebanon War prompted Israel to build a layered missile defense system. Currently, Israel fields the Iron Dome, David’s Sling and Arrow systems.
The Iron Dome is a surface-to-air missile system designed to defend against short-range projectiles. According to figures released by Israeli defense officials, Iron Dome has a 90% hit success rate and during Operation Pillar of Defense in 2012 the system was credited with hitting 84% of incoming projectiles.
These figures, however, are contested by some analysts, with their claimed 90% success rate not supported by public evidence. In addition, Iron Dome proved ineffective against even shorter-range rockets and mortar attacks launched from nearby Gaza, which has driven Israel to develop laser-based defenses to augment the system.
David’s Sling is the next layer of Israel’s layered missile defense system. It is designed to defeat short-range ballistic missiles, large-caliber rockets and cruise missiles at an altitude of 15 kilometers and a range of 45 to 300 kilometers.
Unlike the Iron Dome’s Tamir interceptors, David Sling’s Stunner missiles contain no explosive warheads and use hit-to-kill to destroy their targets similar to the US Terminal High Altitude Area Defense (THAAD) system. However, in contrast to the Iron Dome’s US$50,000 price tag per interceptor, each THAAD Stunner missile costs US$1 million.
The Arrow system, meanwhile, forms the theater-level layer of Israel’s missile defense system and is intended to defeat short and medium-range ballistic missiles. It uses two interceptor missiles, the Arrow 2 and Arrow 3, both of which have directed-fragmentation explosive warheads.
The Arrow 2 has an estimated coverage of 90 kilometers and a maximum intercept altitude of 50 kilometers, while the exoatmospheric 2-stage Arrow 3 can reach double the altitude of the Arrow 2.
Russia has a long history of developing missile defense systems, with Soviet engineers starting work on such in the 1950s and successfully intercepting an intermediate ballistic missile in 1961. After the breakup of the Soviet Union, most missile defense projects were stopped but some were preserved.
At present, Russian doctrine follows a three-tiered approach, allowing the creation of anti-access/area-denial bubbles to preserve its nuclear deterrent and ensure regime survival.
The first tier of Russia’s missile defense systems includes long-range systems such as the S-500, S-400 and S-300. The S-500 is the latest of these systems, which entered serial production this year. It is designed to counter stealth aircraft, ballistic and cruise missiles and low-orbit satellites.
According to official Russian sources, the S-500 can engage targets at an altitude of 100-200 kilometers and a range of 500-600 kilometers, depending on the target’s size, speed and radar cross-section. In May 2018, a US intelligence source said that the S-500 struck a target 481 kilometers away during a test, showing the S-500’s missile-hitting prowess.
Russia’s second-tier defenses consist of the mid-range Buk M3 surface-to-air missile and its variants. The Buk M3 is designed to increase radar coverage of air defense zones and at the same time supplement limited inventories of long-range air defense missiles.
Although the system first entered service in 1980, it has been steadily upgraded to the point that the latest M3 variant is reportedly more capable than older generation S-300 systems. With its new 9M317M missiles and upgraded electronic components, the so-called Buk M3 has a maximum engagement range of 70 kilometers, minimum engagement range of 2.4 kilometers and maximum engagement altitude of 35 kilometers.
The last tier of Russia’s missile defense system consists of short-range systems that are often attached to ground units for low-level air defense and higher-tier Russian missile defense systems to offset their vulnerability against low-flying threats. They also provide point defense for critical assets. Such systems include the Tunguska and Pantsir combination gun-missile launchers and the Tor short-range missile system.
The wars in the Middle East and Ukraine have cast doubts on the performance of Russia’s second and third-tier defenses. In 2020, at least 23 Pantsir systems were destroyed by Turkish Bayraktar and Anka drones in Syria and Libya, despite the fact the systems were expressly designed to counter these low and slow flying threats.
Moreover, Ukrainian drones continue to fly despite the presence of strong Russian electronic warfare capabilities and air defense systems, with an older Buk M1 launcher destroyed by a Ukrainian Bayraktar drone. These losses may have motivated Russia to expedite the deployment of its laser weapons to counter the Ukrainian drone threat.
China fields a similar layered defense system, fielding both Russian-bought and domestic platforms. In designing its missile defense system, China seems to have combined elements of Russian and US systems to combine the best features of both.
Its first-tier missile defense systems include the Russian-bought S-400 and the HQ-9 interceptors. The S-400 is a mobile long-range surface-to-air missile system capable of engaging targets up to a range of 400 kilometers It carries two separate radar systems, which can detect aerial targets to a range of 600 kilometers and can simultaneously engage 80 aerial targets.
This is supplemented by the indigenous HQ-9, which is derived from the Russian S-300 and US Patriot systems, having several variants with ranges of 100 to 300 kilometers. China is also developing a successor to the HQ-9 known as the HQ-18, which is reportedly reverse-engineered from the newer Russian S-300V and is reputedly capable of intercepting hypersonic weapons.
For its second line of missile defense, China also fields the HQ-19 interceptor, which is analogous to the US THAAD with a hit-to-kill interceptor instead of an explosive warhead. It also has the DN-3 hit-to-kill interceptor, which is roughly on par with the US Standard SM-3 missiles used by the Aegis system.
China also uses the HQ-16, which incorporates elements from Russia’s Buk air defense system but uses a vertical launch configuration to give it 360-degree coverage. Another notable Chinese mid-tier missile defense system in development is the HQ-29, which is a counterpart to the US Patriot PAC-3.
The HQ-29 combines highly responsive airframe and altitude control motors to generate an angle-of-attack that would not be achievable with actuator-driven aerodynamic control surfaces alone.
For its third layer of missile defense, China employs short-range missile systems and combination gun-missile launchers. The mainstay of China’s short-range missile defense includes the HQ-7 system reverse-engineered from the French Crotale missile launcher.
It also employs the Type 95 combination gun-missile launcher equipped with four 25-millimeter cannons and four QW-2 short-range heat-seeking missiles. As with Israel and Russia, China is also developing laser weapons for its J-20 fighter, which could give it defense capabilities against hypersonic missiles.
While Israel, Russia and China deploy formidable, complex and expensive layered missile defense systems, they are by no means fool-proof. In almost all cases, it is not high-tech missiles that pose the greatest threat to these layered defenses but low-cost saturation assaults, including swarming drone attacks, that have defeated these costly and mostly unproven systems.
For Israel, it could be argued it called for a ceasefire during Operation Protective Edge in 2014 not because it had achieved its military objectives but rather because it had run out of interceptor missiles. Hamas fired thousands of rockets against Israel and ended the conflict with its capabilities still intact, essentially winning by not losing.
For Russia, the fact that Ukrainian drones are blowing up its air defense systems which were designed specifically to shoot them down is confounding. This startling success of Ukraine’s drones can be attributed to multiple factors, such as Ukrainian electronic warfare capabilities, smart drone tactics and Russia’s perplexing decision to withhold most of its air force from the fighting in Ukraine.
For China, recent simulations have shown that drone swarms may be key to defending Taiwan against a Chinese invasion – provided that any such conflict stays within non-nuclear bounds.
Drone swarms could be deployed together with stealthy manned platforms such as the F-35 and F-22 to hit Chinese missile batteries, flood enemy radar scopes with multiple targets and force them to waste limited missiles and ammunition on expendable decoys before manned systems or missile strikes are launched.
While currently no missile defense system can defend against hypersonic weapons, it may still be possible to defend against them. Current midcourse-intercept missile defenses can’t defend against hypersonic glide vehicles, as they fly at a lower altitude and atmosphere than traditional ballistic missiles.
Existing space and terrestrial radars may also have difficulty tracking lower-altitude maneuverable gliders. However, since hypersonic weapons are slower than an intercontinental ballistic missile (ICBM) during their terminal phase, meaning it might be possible to intercept them during that stage of flight.
As such, future missile defense concepts may emphasize terminal, narrow area defense rather than global or regional coverage. While global and regional interceptor-based defense systems won’t become obsolete overnight, they may be complemented by numerous directed-energy point defense weapons such as lasers that can shoot down missile volleys, drones, and hypersonics in their terminal flight stage.
The US, Israel, Russia and China have all developed prototype laser weapons that can perform such roles. However, laser weapons pose their own technical challenges, such as huge power consumption, high initial costs and relatively bulky equipment that limits maneuverability.
While missiles destroy their targets instantaneously on impact, a laser must be focused on a target for a few seconds to destroy it, which may not be desirable for targets moving at thousands of kilometers per second.
Still, advances in laser technology including more efficient and compact power sources, artificial intelligence-assisted beam modulation and further miniaturization of key components are making the idea of low-cost, numerous and dispersed laser-based missile defenses an emerging reality.
In the long term, as envisaged by Reagan’s SDI, space-based directed-energy weapons will be the best defense against ballistic missiles in both boost and mid-course phases. This will not make terminal phase missile defense and defense against hypersonics obsolete. It will, however, be capable of nullifying a substantial portion of the 10,000 or so nuclear ballistic missiles now in service – over 90% of which are owned and operated by the US and Russia.