From SDI to BMD: the evolution of the US anti-missile shield (ARI)

From SDI to BMD: the evolution of the US anti-missile shield (ARI)

Resumen en Inglés

Theme: This ARI reviews the gestation, evolution and current situation of anti-missile defence in the US, from its Strategic Defense Initiative (SDI) to its Ballistic Missile Defense (BMD).

Summary: BMD (Ballistic Missile Defense) is a controversial programme proposed by President George W. Bush with the aim of protecting the US, its allies and troops deployed around the world against a limited ballistic missile attack. This system is currently designed to protect against threats from North Korea and Iran, but it is expected that it will soon be extended to have world-wide coverage. To this end, Bush has not only maintained contact with countries like Australia, Canada, the UK, Japan, the Netherlands and Denmark, which from the outset registered their interest in participating in one of the BMD systems, but has also sought new commitments from countries including Poland, the Czech Republic and Georgia for deploying the detection, monitoring and interception devices for ballistic vectors.

In view of its strategic, military, political and technological implications, BMD –generically known as an ‘anti-missile shield’– is the subject of heated debate within the international community. The roots of its implications must be sought in President Ronald Reagan’s SDI (Strategic Defense Initiative), the so-called ‘Star Wars’, as well as in its more direct predecessors, both George Bush’s Global Protection Against Limited Strikes and Bill Clinton’s National Missile Defense. Thus, the anti-missile shield is not only a dynamic project which advances in tune with technology and the strategic environment, but it can also be seen that, since 1983, all US Administrations, regardless of their political hue, have been involved in its development to a greater or lesser extent.



The US’s determination to protect itself from a ballistic missile attack is not new. Even prior to the Soviet Union’s launch of the first artificial satellite in 1957, and its first intercontinental ballistic missile (ICBM) in 1959, Washington had already begun to explore systems inspired by this aim. In the 1960s, the US presented the first anti-missile systems featuring detection by means of rockets armed with nuclear warheads designed to destroy missiles by detonating them within the atmosphere or outside it. However, of the three big projects presented during this decade (the DefenderSentinel and Safeguard systems) only the latter achieved limited operability in 1975, being deactivated shortly afterwards because of its high costs and low reliability.

Fearing that dissemination of these systems would alter the doctrine of Mutual Assured Destruction (MAD), in 1972 the US and the Soviet Union signed the Anti-Ballistic Missile –ABM– Treaty, which limited the numbers and locations of anti-missile systems that the two superpowers could deploy to defend themselves against possible nuclear strikes. The signing of this agreement and subsequent deployment of the first ballistic missiles armed with multiple warheads (Multiple Independently Targetable Reentry Vehicle, MIRV) re-established the balance of terror for the remainder of the decade.

The Reagan Administration reinitiated the research into ideas to overcome the strategic stalemate that MAD entailed. Its first response was the implementation of the Nuclear Utilization Target Selection (NUTS), which, alongside the entry into service of a new generation of more precise ballistic missiles, such as MX Peacekeeper and Trident D5, were designed to allow a limited nuclear option if dissuasion failed. The second response was the controversial SDI (Strategic Defense Initiative).

‘Star Wars’ was an ambitious project seeking to protect the US against a hypothetical Soviet nuclear attack, thereby ensuring that its enormous atomic arsenal became obsolete and shifting the fragile nuclear balance between the superpowers in the US’s favour. The programme was severely criticised, both because of its astronomical costs and the technical limitations of the period, which proved incapable of supplying the satellites, sensors and arms that this project required. Although it was soon demonstrated that it would be impossible to create an impenetrable shield to safeguard American territory from a massive nuclear attack, SDI did allow the US to regain the strategic initiative that it had not wielded since the Vietnam War, and it also dragged the Soviet Union into a new technology and arms race that its weak economy was unable to support.

In 1991, coinciding with the end of the Soviet threat, SDI was formally cancelled and replaced by another, less ambitious, system more in keeping with the strategic reality of the immediate post-Cold War period: Global Protection Against Limited Strikes (GPALS). This project sought to protect American territory from ‘accidental, unauthorized or deliberate’ launches of a maximum of 200 ballistic missiles from the former Soviet republics or China. This concern was evident in Base Force (1989-92), which sought to establish the strategic pillars and to catalogue the capacities on which post-Cold War American defence and military policy should be constructed. It assumed that while China would maintain its regional strategy and territorial pretensions, Russia would adopt a defensive strategy. But it alerted to the possibility that a power vacuum, struggle for power or the hypothetical reconstitution of the Soviet Union could present a limited nuclear threat. As a secondary measure, GPALS would also be required to guarantee zonal defence for forces stationed abroad; a requirement inserted by the US Congress in the light of the fears which the Iraqi Scud missiles raised on the American lines during the 1991 Gulf War. GPALS was maintained formally active until 1996, although the development of this ambitious project was stymied by a lack of financing due to the existence of more pressing needs.

As the new strategic environment was being formed and the threat from the Russian nuclear arsenal was declining, it became increasingly obvious that the proliferation of weapons of mass destruction and means for launching them was growing in the rogue states. US fears in relation to this situation were first evidenced in the Bottom-Up Review (1993) –vaunted as the great post-Cold War US defence review– which recommended increasing the anti-proliferation system and maintaining effective nuclear dissuasion, developing active counter-proliferation measures and driving forward an anti-missile system with national coverage in order to offset the possibility of this new threat. Initial studies indicated that these nuclear weapons and the means of launching them could begin appearing in around 2010. Subsequent analyses, such as that of the Commission to Assess the Ballistic Missile Threat to the United States in 1998, a working group established at the request of the US Congress –controlled by the Republican Party– which was led by the future Defence Secretary, Donald Rumsfeld, reduced this timescale on the basis that North Korea and Iran could acquire the capacity to build ballistic missiles armed with nuclear or biological warheads in 2003, and Iraq in 2008. The commission’s conclusions ratified the contents of the 1997 Quadrennial Defense Review, which established the strategic aims, military resources and capacities that the US should generate for the period 1997-2001. The final document held that North Korea, Iran and Iraq would have the capability to manufacture weapons of mass destruction and ballistic missiles in the short-term, and therefore recommended the intensification of anti-proliferation and counter-proliferation measures, the strengthening of dissuasion and the driving forward of an anti-missile shield in accordance with the ideas detailed in 1996 by Defence Secretary William Perry who, after assessing the conclusions of the Ballistic Missile Defense Program Review, ordered the implementation of an anti-missile system to be operative by 2000, and the securing of the financing necessary for the same.

The following year, the two US legislative chambers, both controlled by the Republicans, ratified this decision by passing the National Missile Defense Act, which impelled the government to develop National Missile Defense (NMD) by 2004. NMD was to be capable of defending the US against a limited ‘accidental, unauthorized or deliberate’ strike of between five and 20 ballistic missiles, and would offer the possibility for expansion in accordance with the requirements of the strategic situation. This project was complemented with Theater Missile Defense (TMD), which focused on the protection of American troops abroad. NMD was initially targeted on North Korea, the rogue state that had the most advanced nuclear and ballistic programme. The US deployed devices to detect the launch of missiles, monitor their course and intercept them during the central phase of flight in California, Alaska, the UK, Greenland and via resources in the Atlantic and Pacific oceans, and also negotiated with allies in the region –Japan, South Korea and Australia– for them to join the initiative.

Concerned by North Korean advances, Japan had begun negotiating with the US in 1993 on its participation in three zonal defence programmes integrated in TMD, which are today part of BMD (Ballistic Missile Defense): the Terminal High Altitude Area Defense System (THAAD), in which South Korea also wants to participate, the Patriot missile PAC-3, and the tandem formed by the sea-based combat system, Aegis, and the SM-3 Standard missile. After a North Korean missile was flown over Japanese territory in 1998 and in the light of Pyongyang’s decision to continue its nuclear programme in 2002, Japan decided to accelerate acquisition of these systems while simultaneously authorising the US to station a detection radar for ballistic ICBMs on its territory, to be built in the following months and employed by both the Japanese and US systems. In addition, in mid-2003, Australia agreed with Washington the installation of an early warning base and a missile monitoring station to form part both of BMD and the Australian anti-missile system, a theatre defence system that would employ land, and naval resources to offset limited ballistic threats.

A number of technical problems, along with North Korea’s acceptance of a moratorium on the development of its intercontinental ballistic missile programme, initially delayed the entry into service of NMD –integrated within the current anti-missile shield under the name of Ground-Based Midcourse Defense– until 2006. NMD caused deep unease in China and Russia, who felt that this system was directed against them, and that its entry into service would alter the existing strategic balance between the US and the two countries. In Russia’s case, this argument lacks substance in view of the fact that the country could easily saturate the system with the 300 ballistic missiles that it maintains. China, however, only possesses 20 ballistic vectors capable of reaching the American continent; meaning that, in theory, the US could become immune to Chinese dissuasion, gaining unprecedented freedom of manoeuvre to intervene militarily in Asia. In the light of this situation, Beijing issued a warning that NMD would oblige it both to develop active means to target destruction of American detection and monitoring satellites and to increase its ballistic arsenal; a decision that could mean the start of an escalation in military tensions capable of altering the regional equilibrium.

Washington also commenced conversations with Moscow to modify the ABM treaty and thereby allow for the development of the American anti-missile shield. In 1999, the United Nations passed a resolution urging the US to abandon its plans to build this system. In September 2000, the US already had the technical capacity available to develop and launch NMD within six years, but President Clinton postponed any decision until after the presidential elections. With the triumph of the Republican Party, deployment of the anti-missile shield was confirmed and President Bush proceeded to roll out the system regardless of international criticism and Moscow’s reservations in regard to modification of the ABM treaty, from which it eventually withdrew at the end of 2001, three months after the September 11 terrorist attacks on New York and Washington.

Both the Quadrennial Defense Review of 2001 –the guidelines for the new government’s defence and military strategy for the period 2001-05– and 2002’s Nuclear Posture Review, which detailed the structure, volume, capacities and employment doctrine of US nuclear forces, stressed the importance of having available a wide range of active and passive defence resources in the face of ‘new threats’. At the end of the year, President Bush asked the Department of Defense to begin preparations for deployment before the close of 2004 of an anti-missile shield capable of protecting the US, its deployed forces, and allied countries against ballistic missile strikes. This system would be called ballistic missile defence (BMD).

Ballistic Missile Defense (BMD)

As opposed to its predecessor, designed to offset limited ballistic missile strikes by means of land and naval resources to intercept enemy missiles during the mid-flight phase, BMD is a much more ambitious system, integrating NMD (designed for territorial defence) and TMD (focused on providing coverage for deployed units) in a single project focusing on the use of a plethora of land, sea, air and space resources to destroy enemy missiles in the three flight phases (initial, mid-course and final). To destroy missiles in the initial phase, a period of time of less than 300 seconds in which the rocket gathers the speed required to reach its target, the US is developing an Air-Borne Laser (ABL), flown in a Boeing 747, which will locate, track and destroy all short, mid and long range missiles, along with a Kinetic Energy Interceptor (KEI) mounted on land or marine platforms and able to hit to kill by impact.

Two initiatives are being developed with a view to intercepting enemy missiles in the central flight phase, a long period in which the missile’s warhead advances towards the target following a parabolic trajectory easy to predict: first, Aegis Ballistic Missile Defense, which employs the Aegis combat system mounted on vessels, including those of the US Navy, alongside the Standard SM-3 missile, to destroy short and mid-range missiles. Secondly, Ground Based Midcourse Defense (GMD), the name given to President Clinton’s NMD since its inclusion in the BMD, which is the only system that has been operative service since 2006, employing land and sea locations to detect, monitor and intercept the missile by means of collision. It is precisely GMD that the US has decided to extend in Europe, deploying sensors and interceptors in the Czech Republic and Poland respectively.

In order to intercept enemy missiles in their final phase, a brief period running from the entry of the warheads into the atmosphere to their impact on the target, the US is developing and integrating four systems. First, the aforementioned THAAD, capable of destroying enemy missiles at high altitude as they commence their descent to their target. Secondly, the Arrow missile, a joint US-Israeli initiative, designed to intercept short and mid-range missiles in the stratosphere. Thirdly, the Patriot PAC-3, an improved version of the Patriot anti-missile system which achieved such fame during the 1991 Gulf War, to be employed to destroy missiles at mid-altitude and which will constitute the primary interceptor of the Medium Extended Air Defense System (MEADS), developed by the US, Germany and Italy. It will provide anti-air and anti-missile coverage to deployed forces, filling the existing vacuum between point and zonal defence. The crowning point of all of these devices will be a system of command, control, communications and combat management to pool and process the information obtained by the different sensors (missile localisation, situation, trajectory, target, etc) and forward it to the anti-missile system for missiles to be intercepted and destroyed.

Conclusions: BMD is a controversial project seeking to protect the US, its allies and American forces deployed abroad against a hypothetical limited ballistic missile strike from a rogue state such as Iran or North Korea, although it is expected to be extended to cover a higher number of threats over the coming decades; to the point where it becomes a global anti-missile shield.

To this end, an ambitious system is being developed, supposedly capable of locating, tracking and destroying all enemy ballistic missiles in all phases of flight, from launch right up to just before impact, and featuring a plethora of land, naval, air and space resources, most of which are still undergoing development. However, the first of these shields systems was declared operative in 2006 and the aim is for most of the remaining devices to be functional by the end of the present decade.

The deployment of BMD is provoking fierce debates within the international community, which is worried about the possible consequences of this initiative. While it is generally accepted that nuclear and ballistic proliferation constitutes a threat of a global nature, it is also believed that the American anti-missile shield may upset the global strategic balance. Furthermore, although BMD’s main aim is to eliminate the North Korean and Iranian ballistic threat, the American commitment to facilitate Japan and Australia with theatre anti-missile defence systems and to station warning and monitoring systems on their territory, on the one hand, and the recent agreements reached with the Czech Republic and Poland to install monitoring and intercepting devices, on the other hand, have to Chinese and Russian fears that the anti-missile shield is directed against them. Although many of their arguments are completely devoid of substance, the truth is that the first effects of this situation have been quick to appear: Russia has suspended the FACE treaty and is threatening to review its military policy, while China might choose to speed up development of its anti-satellite systems so as to be able to destroy the American observation and recognition satellites, should the need arise, while also increasing and modernising its ballistic arsenal; a decision that would lead to the start of an escalation in military tensions that could alter the regional balance.

Development of the programme depends on internal variables such as the support of future Administrations, as well as on external variables such as technological advances and the cooperation of other allies. Conditioned by so many factors, it is not easy to forecast its future, but BMD has already achieved short-term results and is currently on course to obtain mid-term goals. If critics, detractors and the great difficulties it gave rise to were unable to stop development of ‘Star Wars’, is it likely that they will now be able to halt a project that appears to be much more tangible and less controversial?

Guillem Colom Piella
Defence analyst