Existing US air defense systems have not proven reliable enough for purpose
By Stephen Bryen
The US needs a new start in air defense. Existing systems are not integrated, not layered, and are mediocre to poor performers. Since the 1950’s the US has struggled for solutions to missile threats. Because the Army and the Pentagon keep trying to improve the one system they have instead of creating a real competitive environment, the future for US missile defense and US security seems bleak.
This is nothing new. US history in air defenses has been less than stellar.
On May 22, 1958 at Leonardo New Jersey at approximately 1:20 in the afternoon, eight Nike Ajax missiles at Leonardo Battery B, 526th Anti-Aircraft Missile Battalion, exploded, killing 10 men, six from the army and four civilians at the base.
Nike Ajax bases had been placed around the United States to guard against Soviet nuclear bombers, especially the Tu-95. Each Nike Ajax missile had three explosive warheads. The missiles had a slant range of around 30 miles, in the Leonardo Battery sufficient to provide good coverage of New York unless a bomber approached inland from the north. Other Nike Ajax Battalions would protect the city from that direction.
But the Soviets quickly started building long range intercontinental ballistic missiles, Khrushchev said the USSR was “grinding them out “like sausages” it was said. These nuclear missiles could not be defended by Nike Ajax. Thus, when Leonardo Battery B’s eight missiles exploded the base was preparing to soon install Nike Hercules, to replace Ajax. These had a longer range (100 miles) and differed from the Ajax in one critical respect: the warhead was a boosted nuclear fission (W-31) weapon with an explosive power of 20 kilotons (KT). The bomb that destroyed Hiroshima was supposed to be 18 KT, but in fact was closer to 16 KT. The idea of Nike Hercules was to destroy Russian missiles with radiation, not the nuclear blast itself.
The US planned a follow-on to the Nike Hercules (Nike-X) with more than double the range and an even bigger thermonuclear warhead. It was planned to protect US missile fields in the Midwest. The program started in 1961 but was cancelled in the Kennedy administration by Robert McNamara in 1963. The cancellation has largely been explained for technical reasons, but in fact after the Cuban Missile Crisis Kennedy and Khrushchev had reached a deal that eventually led to various treaties including SALT 1 (discussions for the treaty started in 1967) and the now cancelled Anti-Ballistic Missile Treaty (first proposed at the Glassboro, NJ Summit in 1967). It is said the main motivator for the ABM Treaty was multiple warhead ballistic missiles (later MIRV, Multiple Independently Targeted Reentry Vehicles) –in the Pentagon judgment there were too many warheads and decoys (also known as “penetration aids”) that would overwhelm any missile defense.
Instead of protecting cities, the Johnson and Nixon administrations turned to the idea of protecting US missile bases. Two programs were started —Sentinel in 1967, cancelled in 1969, and Safeguard, a two layer system. Safeguard had two different missiles –an exoatmospheric interceptor called Spartan that carried a 5 megaton thermonuclear warhead (5,000 KT); and an atmospheric shorter range intercept called Sprint with a 1 Kt thermonuclear warhead. Because of the 1972 ABM Treaty the US (and the USSR) were limited to two ABM sites. There were two Safeguard sites, one in North Dakota and the other in Montana. In 1974 the US and USSR decided to reduce ABM bases to one each, and the US only kept the North Dakota installation, but only for a year. Congress ordered it deactivated in 1975.
Today no US city and no US missile base in the United States has protection against ICBMs or any other threat. In California at Vandenberg AF Base and Alaska at Ft. Greely. the US deploys the Ground Based Midcourse Interceptor (a total of 44 interceptor missiles). The missile has a spotty record of tests ( 11 of the 20 [55%] hit-to-kill intercept tests have succeeded) and the Air Force is looking for a replacement missile. GBI is exoatmospheric and uses “hit to kill” technology –it does not have an active warhead. In the Air Force approach, GBI with a new interceptor missile will still be limited to rogue missiles from North Korea (GBI is not deployed to deal with Iran). Even though the ABM Treaty is cancelled, there appears to be no interest at the Pentagon or Congress for a real ABM capability to protect United States territory.
Tactical Missile Defenses
The US has evolved the MIM-104 Patriot system for land-based intercepts of tactical ballistic missiles. The Navy has SM-3 1B interceptor missiles that can also intercept ballistic missiles deployed on US Aegis cruisers.
PAC-3 Patriot is generally regarded as the top US tactical ballistic missile defense system. It can launch different interceptor missiles. Patriot in the last few years has been observed in Saudi Arabia where the system has intercepted, or partially intercepted Yemen-based Houthi fired ballistic missiles (originating in Iran). Patriot has also been used against cruise missiles. Overall Patriot’s performance (PAC-2 and PAC-3) has been mixed. It intercepts missiles during the last moments of the flight trajectory and appears to have trouble distinguishing between missile bodies and missile warheads (particularly in new Iranian missiles where the warhead separates in the last seconds from the missile body). Also, judging from shot down missile debris, the system can hit an incoming missile but not fully destroy it.
The US does not have layered missile defenses –that is, tactical defense systems that can deal with threats that can include different kinds of ballistic missiles, cruise missiles, aircraft and even drones (including loitering munitions). The upshot is that the US has serious difficulty in being able to protect overseas US bases.
An example of what can happen was Operation Martyr Soleimani by Iran’s Islamic Revolutionary Guard Corps against two US bases in Iraq –Ayn al-Asad and Erbil, using ballistic missiles. In all 22 missiles were fired, 17 at the Ayn al-Asad base and 5 fired at Erbil. While there was some forewarning and US personnel were sheltered, the blast effects of the rockets caused 110 casualties (mainly in the form of serious concussions). The US had no air defenses of consequence at either base.
Today the US Army is working on an integrated tactical air defense system, but will rely on Patriot as the main tactical missile defense component. There is no thought about replacing Patriot or balancing Patriot with other systems that can destroy tactical ballistic missiles such as the kind that crashed into Ayn al-Asad or Erbil. Having all eggs in one basket is the Achilles heel of US defense programs.
Russia takes a significantly different approach and has many different air defense systems they say cover the spectrum of threat, ranging from the highly promoted S-400, the S-300, Pantsir, Tor, 9K31/9K32 Strela, Osa, Buk, Pecora and the forthcoming S-500. All these systems are mobile and are supported by many different types of radars (passive and active). The Russians also deploy advanced jammers both to protect their air defenses and to destroy incoming threats where possible. Because today most precision guided weapons use GPS (US, Russian, Chinese or European) they can be jammed or spoofed.
Israel has deliberately built a layered air defense system which can handle everything from short range rockets, drones and cruise missiles to long range intermediate range ballistic missiles. Among the Israeli systems are Iron Dome, David’s Sling, Arrow II and Arrow III. Israel also has Patriot primarily for anti-aircraft use. One feature of Israel’s approach is an Air Defense Command, allowing it to coordinate its operations and optimize against a bevy of potential threats.
Today the difference between tactical missiles and long range missiles has all but disappeared since tactical missiles can have conventional warheads or unconventional ones (nuclear, chemical and biological). Although there is no defense system that can offer perfect protection, a layered system under a single command authority appears to be the best approach (even if the command authority is virtual and distributed to assure survival). Furthermore there is no such thing as a purely defensive system. The attacker has to know that he will be attacked and pay a severe price.
The US, after the various failed or cancelled programs of the 1950’s and 1960’s needs to reexamine continental and expeditionary air defense. It can’t rely on a couple of systems (such as GBI or THAAD) to knock out an errant missile or halt a North Korean nuclear attack. Put simply, the US systems are not thoroughly reliable even in this posture. Threats coming from near-peer adversaries (Russia, China) and from ruthless actors such as Iran, make clear that the US needs urgently to upgrade its thinking and open itself up to a variety of solutions to have credible air defenses to protect its territory and its overseas bases and expeditionary forces.