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Summary Article: Missile Defense
From Science and Politics: An A-to-Z Guide to Issues and Controversies

In his speech before Congress in October 1945, President Harry Truman famously remarked that “Every new weapon will eventually bring some counterdefense against it” (quoted in Brodie 1946, 30). There are two basic forms of defense: active and passive. The former aims at reducing the number of incoming enemy weapons, while the latter is about the ability “to absorb those weapons that actually strike home” (Brodie 1959, 181). To shield against various types of hostile missiles, both carrying conventional and nuclear warheads, some states (e.g., the United States, Russia, France, Israel, Japan, and India) have developed missile defense (MD) systems— one of the most high-tech and potent, though yet not fully effective, examples of active defense.

Scientific Background

MD systems can be divided into several categories depending on characteristics such as:

  • Ranges and types of missiles intercepted

    • Theatre MD: against short- (under 1,000 kilometers) and medium-range (1,000–3,000 kilometers) ballistic missiles (SRBMs and MRBMs)

    • Strategic MD: against intermediate-range (3,000–5,5000 kilometers) and intercontinental (over 5,500 kilometers) ballistic missiles (IRBMs and ICBMs)

  • The trajectory phase during which the intercept occurs

    • Boost phase: rising through the atmosphere from the launch until the end of powered flight of the main stages of the missile (which takes 3–5 minutes)

    • Midcourse phase: missile coasts through space on a ballistic course (up to 20 minutes for ICBMs)

    • Terminal phase: missile's warhead falls back into the Earth's atmosphere over the target (less than a minute)

  • Size of the protected area: tactical, theatre, and strategic MD

Historically, constructors have faced a unique set of technological challenges because a fully deployable comprehensive MD must detect and identify enemy targets, which requires a powerful network of radar systems and satellites; track the trajectory of the enemy missile and guide the interceptors; and assess damage and if necessary fire additional interceptors or trigger the next tier of defense (Burns 2010, 41).

MD systems consist of three key components: an advanced early warning system (series of interlocking radar systems, satellites, and sensors); antimissile interceptors; and computer, communication, command, and control systems. A credible MD would be a multitier (boost, midcourse, and terminal phase) system that automatically activates the subsequent layer if the previous one fails.

Initially, early antimissiles carried (thermo) nuclear warheads intended to destroy a hostile nuclear armed missile by means of a nuclear explosion, blast, and X-ray. This would, however, produce a severe electromagnetic pulse and wipe out all electronic devices within the particular range, probably also blinding the MD's radar systems. Therefore, later nonnuclear kinetic-kill vehicles have been developed to destroy a ballistic missile by colliding with it at high speed.

In sum, the major technological challenge has been to detect an enemy missile early enough to launch antimissiles, track its trajectory, and direct an interceptor. But as the great American strategist Bernard Brodie noted of nuclear weapons, “No adequate defense against the bomb exists, and the possibilities of its existence in the future are exceedingly remote” (Brodie 1946, 28). There have been effective tactical and theatre MDs; however, as technological drawbacks surrounding the current development of American MD have shown, a reliable wide-range and strategic antiballistic missile (ABM) system still remains beyond reach.

Politics and Policy

Since its very beginning, MD has been immersed not only in scientific-technological debates but also in political-strategic controversies.

The Cold War: From Development to Limitations

The “missile age” began in 1944 with the German V-2 rocket strikes against London and Antwerp, which forced the United States to initiate the Thumper project, to explore ways of protecting American forces from the V-2. Following the Soviet Union's development of nuclear weapons in 1949 and the deployment of long-range strategic bombers for their delivery, the United States sought to construct anti-aircraft defense missiles (Army projects: Nike [1945], Nike-Ajax [1953], and Nike-Hercules [1954]). These efforts soon evolved into antiballistic missile programs, notably: Nike-Zeus (1956), Nike-X (1963), Sentinel (1968), and Safeguard (1975), to shield the ICBM fields in Grand Forks, North Dakota). The initial development of American ABMs was shadowed by the interservice rivalry between the Army and the Air Force, with the former finally winning control over the systems in the mid-1950s. On the other hand, the Soviet Union developed MD around Moscow (A-35 or “Galosh” in 1966, later replaced by A-135) and Leningrad (S-500 or “Giffin,” later replaced by S-200 or “Gammon”).

These ABM buildups threatened what American nuclear strategist Albert Wohlstetter described as “the delicate balance of terror” (Wohlstetter 1958). Because ABMs sought to replace deterrence with defense, they challenged the foundation of stable American-Soviet strategic relations—that of mutually assured destruction. The expansion of MDs triggered the arms race and led to a substantial increase in offensive weapons, designed to overwhelm the adversary's ABMs. According to this logic, from 1967 to 1970 the United States developed a multiple independently targeted re-entry vehicle (MIRV)— several warheads carried on a single ICBM, each capable of hitting a different target. As both sides realized that ABMs led to an offensive-defensive arms race, making the balance of terror increasingly less stable, in 1972 the two countries signed the ABM Treaty, which limited each side to one ABM site around each nation's capital and another in an unspecified location (limited further in 1974 to one site only). Each location could be armed with no more than 100 ABM launchers and interceptors. Ultimately, the Soviet Union retained its system around Moscow while the United States kept the Grand Forks site.

Strategic Defense Initiative

In March 1983, President Ronald Reagan announced the Strategic Defense Initiative (SDI), with the aim of building a system that would render nuclear weapons “impotent and obsolete.” If deployed, it would give the United States a tremendous advantage over the Soviet Union. However, the idea raised heated controversies. First, the scientific community doubted the feasibility of the project given the shortcomings of the technology. The science-ficionesque character of the project led critics to dub it “Star Wars” and Time called it a “videogame vision” (Isaacson 1983). Second, the project was a huge drain on funds, with costs estimated at about $40 billion. Third, it generated tensions and mistrust among European allies who feared that the United States might become less committed to their defense. Fourth, SDI was but a part of Reagan's intensive military buildup (e.g., MX ICBM, Trident II D-5 submarine-launched ballistic missile [SLBM], Pershing II IRBM, and B-1 bomber). Although he wanted to force the Soviets into a financially draining arms race to bankrupt the communist state and bring down its regime, the plan did not work for a number of reasons. First, Mikhail Gorbachev responded asymmetrically, surprising the United States with various disarmament/arms limitation initiatives. Second, the Soviets doubted the credibility of SDI; for example, Andrei Sakharov argued that it was a kind of “Maginot line in space” that would not stop Soviet ICBMs, akin to the French Maginot line that did not stop the Germans in 1940 (Burns 2010, 46). In sum, Reagan based his proposal on foreign policy assumptions, personal preferences, and domestic politics rather than on technological feasibility.

American Strategic MD for the Twenty-first Century

Due to the lack of technical progress, President George H. W. Bush postponed Reagan's project. However, the post–Cold War proliferation of weapons of mass destruction and missile technology restored MD as a political issue, with the Republican Party calling for the development of a system to protect the American homeland. This was one of the reforms promised in the Republican Contract for America during the 1994 Congressional election campaign. Security and intelligence experts disagreed on the assessment of the missile threat from such “rogue states” as Iraq, Iran, and North Korea. The reassuring findings of the 1995 National Intelligence Estimate 95–19 were questioned by the alarming conclusions of the 1998 Rumsfeld Commission Report, which almost immediately received compelling confirmation in the North Korean launch of its Taepodong-1 missile. It was in this context that Congress passed The National Missile Defense Act of 1999, which declared that “It is the policy of the United States to deploy as soon as is technologically possible an effective National Missile Defense system capable of defending the territory of the United States against limited ballistic missile attack” (The National Missile Defense Act of 1999, sec. 2). President Bill Clinton ceded the decision on the development of the system to his successor George W. Bush, who was enthusiastic about the project and in 2002 ordered the deployment of an as-yet untested system. Initially it was planned to be composed primarily of twenty ground-based midcourse interceptors (launching a kill vehicle to destroy the target in a high-speed collision) located in Alaska and at Vandenberg Air Force Base, twenty sea-based Aegis interceptors deployed on three vessels, Patriot PAC-3 units, twenty-four satellites, five ground-based early-warning radar systems, and sea-based Aegis radar systems. To develop the system, the Missile Defense Agency (MDA) was set up within the Department of Defense (DOD) as a successor of Reagan's SDI Organization (renamed to Ballistic Missile Defense Organization in 1993).

The project of the new American MD has generated numerous controversies. First, the technological feasibility and operational reliability of such a nationwide system have been questioned, in particular given the many failures in the intercept tests. Furthermore, even if successfully deployed, its effectiveness could be negated by various countermeasures such as decoys. Second, there is a question of cost-effectiveness. While between the mid-1980s and 2007 the United States spent about $107 billion on MD, in 2008–2013 it planned to spend $49 billion. The additional cost of production, operations, and maintenance could add up to a further $150 billion. Under the Bush administration, MDA spent as much as $57 billion (Missile Defense Acquisition 2007, 1; Burns 2010, 3; Siracusa 2008, 103). Third, critics claim that a more serious threat for the United States than a missile strike would be an attack from the inside (e.g., terrorists exploding a dirty bomb or launching a cruise missile from a boat at the U.S. coast). A counterargument, however, goes that in the wake of the attacks on September 11, 2001, the United States must develop all available preventive measures. As James Lindsay and Michael O'Hanlon testify, “a national security policy that deliberately leaves the American people vulnerable to attack when technology makes it possible to protect them is immoral and unacceptable” (quoted in Siracusa 2008, 85). Fourth, even the mere idea of developing MD had a highly destabilizing effect on the global strategic balance and triggered a hostile reaction, mainly from Russia (due not only to waning Russian striking capabilities but also to the expansion of American MD network into Central and Eastern Europe, i.e., Poland and the Czech Republic) and China (for endangering its comparatively limited strategic offensive capabilities).

In December 2001, to remove legal limitations on the research, development, and deployment of MD, the United States withdrew from the 1972 ABM Treaty, which permitted a theater but prohibited a nationwide system. This unilateral abrogation generated further criticism as the treaty had been perceived as a cornerstone of global strategic stability. Fifth, it contributed to the international perception of the United States as a unilateral power. The European allies had not been consulted initially, which led to a deterioration in transatlantic relations. Later, to alleviate opposition, the United States proposed to extend “the shield” to cover its NATO allies, and in 2007 NATO decided to build its own system to complement the American one.

After reviewing policy and the MDA's programs, President Barack Obama has continued to support the modified version of a limited, active, layered MD. However, given the technical hurdles and political controversies surrounding a nationwide MD system, a more promising success has been seen in the tactical and theater MDs designed for the protection of limited areas and forces such as U.S. Patriot, Japanese theatre MD, and Israeli Arrow and Iron Dome.

Tactical and Theater MD

Patriot is one of the most popular conventional ABMs and is used by the U.S. Army as well as other nations. Developed in 1976, originally as an antiaircraft weapon, it became operational in 1984 and since then has been upgraded (the latest version is PAC-3). Patriot is a truck-towed, highly mobile modular system linked with radar that detects ballistic missiles, cruise missiles, and stealth aircraft. It was used during the Persian Gulf War in 1991 to intercept Iraqi Scud missiles fired against Israel and Saudi Arabia and at that time seemed to be successful. According the Raytheon Company, the Patriot's manufacturer, it was 80 percent accurate in Saudi Arabia and 50 percent accurate in Israel. However, later analysis revealed it actually performed poorly: the U.S. Government Accounting Office confirmed that no more than four Patriots hit their targets, while the Israelis did not experience even a single successful intercept of Scud (Burns 2010, 50–51). Due to this problem of effectiveness, the United States has been interested in expanding its cooperation with other countries, Japan and Israel in particular.

The development of Japan's theater MD was accelerated by the 1998 North Korean launch of a Taepodong-1 missile, which flew over northern Japan. Designed to protect main urban centers against short- and medium-range ballistic threats, the system consists of sea-based Aegis platforms, ground-based PAC-3 batteries, and powerful mobile ground radar sites. Close U.S.–Japan cooperation on its development has stemmed not only from the bilateral military alliance but also from the U.S. interest in providing protection for its troops stationed in Japan and Northeast Asia.


There have been some “timeless” political-strategic issues concerning MD. First, because research, development, production, deployment, and maintenance of these systems is exceptionally expensive, only great powers possess all the necessary technological know-how and financial resources. Second, although an ABM vision often turned into high-tech wizardry, MD has been seen overall as a marvelous system vital for national security because it provides geostrategic defensive leverage. Third, MD systems quickly become outdated by more rapidly developing missile technology. Fourth, by strengthening security of one state, it weakens the striking posture of its competitors, thus forcing them to seek counter technologies and tactics, which usually leads to regional or global arms races. MD always has a substantial impact on strategic military balances, often also raising mounting tensions with allies who might be afraid of becoming less relevant and “abandoned” by their stronger partner. After all, as General Kevin Chilton (the head of U.S. Strategic Command in 2007–2011) remarked, “Missile defense can be destabilizing depending on how you array it” (quoted in Burns 2010, 6).

Bibliography and Further Reading
  • Berhow, M. A. U.S. Strategic and Defensive Missile Systems 1950-2004, Ospring Publishing New York, 2005.
  • Brodie, B.War in the Atomic Age.” In The Absolute Weapon: Atomic Power and World Order, edited by Brodie, B. , 21-69. Harcourt, Brace and Company New York, 1946.
  • Brodie, B. Strategy in the Missile Age. RAND Corporation Santa Monica, 1959.
  • Burns, R. D. The Missile Defense Systems of George W. Bush. A Critical Assessment. Praeger Santa Barbara, CA, 2010.
  • Buxbaum, P. A. An American Iron Dome? International Relations and Security Network (ISN), Zurich, December 20, 2012.
  • Isaacson, W.Reagan for Defense.” Time, April 4, 1983:8-19.
  • Making Sense of Ballistic Missile Defense: An Assessment of Concepts and Systems for U.S. Boost-Phase Missile Defense in Comparison to Other Alternatives. National Research Council, The National Academies Press Washington, DC, 2012.
  • Missile Defense Acquisition Strategy Generates Results but Delivers Less at a Higher Cost. U.S. Government Accountability Office, Report to Congressional Committees, Washington, DC, March 2007.
  • The National Missile Defense Act of 1999. Congressional Record, 106th Congress, 1st Session, Public Law 10638, 106th Congress, July 22, 1999.
  • Performance of the Patriot Missile in the Gulf War. House Committee on Government Operations, 102nd Congress, 1st and 2nd Sessions, 1991-1992, Report102-1086: 179-188.
  • Siracusa, J. Nuclear Weapons. A Very Short Introduction. Oxford University Press New York, 2008.
  • Wohlstetter, A. The Delicate Balance of Terror. Santa Monica. RAND Corporation, November 1958.
  • Łukasz Kamieński
    Jagiellonian University
    Copyright © 2014 CQ Press

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