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National Missile Defense

National Missile Defense (NMD) is a military strategy that has been discussed in the United States since the 1960s. The basic idea is to shield the U.S. against incoming missiles by shooting them down as they approach the country, and its role in nuclear strategy has been a heated topic for several decades. (See also: Anti-ballistic missile)

Table of contents
1 History of NMD
2 References

History of NMD

Nike-Zeus Program

In the late 1950s the Nike-Zeus program investigated the use of
Nike nuclear missles as interceptors against Soviet ICBMs. A Nike warhead would be detonated at high altitudes (60+ miles) above the polar regions in the near vicinity of an incoming Soviet missile. While rocket technology offered some hope of a solution, the problem of how to quickly identify and track incoming missiles proved intractable, especially in light of easily envisioned countermeasures such as decoys and chaff. The Nike-Zeus project was cancelled in 1961.

Ballistic Missile Boost Intercept (BAMBI)

The Nike-Zeus concept of exploding nuclear warheads over the polar regions (or possibly Canada) was hardly appealing. In the 1960s the Ballistic Missile Boost Intercept concept replaced land-launched Nike missiles with missiles to be launched from satellite platforms orbiting directly above the USSR. Instead of nuclear warheads, the BAMBI missiles would deploy huge wire meshes designed to disable Soviet ICBMs in their early launch phase (the "boost phase"). No solution to the problem of how to harden the proposed satellite platforms against attack was found, however, and the program was cancelled in 1968.

The Sentinel Program

In 1967, US Defense Secretary Robert McNamara announced the Sentinal Program which would have a goal of providing a "thin umbrella" of protection against a limited nuclear stike, such as might be launched by Communist China. McNamara recognized, however, that the deployment of even a limited defensive ABM system might well invite a pre-emptive nuclear attack before it could be implemented. This logic (the theory of Mutually Assured Destruction) drove the US and USSR to sign the ABM Treaty of 1972. While the treaty allowed each nation to develop ABM shields for up to two cities or locations, neither country opted to do so.

The Strategic Defense Initiative

In 1983 President Reagan announced a new national missile defense program formally called the Strategic Defense Initiative but soon nicknamed "Star Wars" by detractors. President Reagan's stated goal was not just to protect the U.S. and its allies, but to also provide the completed system to the USSR, thus ending the threat of nuclear war for all parties. A partisan debate ensued in Congress, with Democrats questioning the feasibility and strategic wisdom of such a program, while Republicans talked about its strategic necessity and provided a number of technical experts who argued that it was in fact feasible (including respected Manhattan Project physicist Edward Teller). Advocates of SDI prevailed and funding was initiated in fiscal year 1984. The motivation behind this effort largely collapsed with the fall of the Soviet Union and the end of the Cold War.

President Bush's NMD Program

In the 1990s and early 21st century, the mission of NMD has changed to the more modest goal of preventing the United States from being subject to nuclear blackmail or nuclear terrorism by a so-called rogue state. The feasibility of this more limited goal remains somewhat controversial. Although most (though not all) defense analysts believe that developing a system to intercept a small missile attack is technologically possible, some have questioned whether it is a strategy that is preferable to that of a promise of retaliation.

Key equipment

Recent developments

On December 17, 2002 the US formally requested from the
UK and Denmark use of facilities in Fylingdales, England, and Thule, Greenland, respectively, as a part of the NMD program.

July 2003 Report of the American Physical Society

There has been controversy among experts about whether it is technically feasible at all to build a system which intercepts ballistic missiles during their boost phase, as part of the U.S. National Missile Defense program intends.

This technical criticism came especially from US physicists and culminated in the publication of a very critical study on the subject by the American Physical Society.

The study's main point is that it might be possible to develop within several years from now a system with (though limited) capability to destroy a liquid-fuel propelled ICBM during the boost phase. It was also found possibly feasible to destroy some solid-propellant launches, such as those from Iran, but not those from North Korea, because of differences in the boost time and siting possibilities for interceptors. However, at this time it is to be expected that the likely users of ICBMs will switch to solid fuel, which makes acceleration faster and the boost phase so short that only few tens of seconds remain to identify, target and destroy the missile. The study concluded that this is unlikely to be achievable with expected advances in technology over the following 15 years.

Using orbital launchers to provide a reliable defence against solid fuel launches from Iran or North Korea was found to require at least 1,600 interceptors in orbit. Reducing the requirement to liquid-fueled missile interception would reduce the number to 700. To allow for the use of two or more interceptors per missile, many more would be required.

If operating in the region, within 300km of intercept point for a solid fuel missile, 600km for liquid, the use of the airborne laser was found to possibly be credible, though solid fuel launchers are more resistant than liquid-fueled systems. There is considerable uncertainty about the actual capability of the system.

In summary, the report concluded that:

Given the results that follow from our assumptions, we conclude that while the boost phase technologies we studied are potentially capable of defending the United States against liquid-propellant ICBMs at certain ranges of interest, at least in the absence of counter-measures, when all factors are considered none of the boost-phase defense concepts studied would be viable for the foreseeable future to defend the nation against even first-generation solid-propellant ICBMs.


See also, Nuclear war, Nuclear weapon, Civil defense