Tuesday, November 13, 2012

Strategic Defense Initiative

Missile Defense Test
A U.S. interceptor missile lifts off from Kwajalein Atoll in the Pacific Ocean in December 2001 in a test of a missile defense system. The interceptor successfully destroyed a Minuteman II missile in space, but officials with the U.S. Ballistic Missile Defense Organization said the test was not carried out under realistic conditions. Defense against intercontinental ballistic missiles has long been controversial because of its costs, doubts about its reliability, and its effect on arms control agreements.

Strategic Defense Initiative (SDI), United States military research program for developing an antiballistic missile (ABM) defense system, first proposed by President Ronald Reagan in March 1983. The Reagan administration vigorously sought acceptance of SDI by the United States and its North Atlantic Treaty Organization (NATO) allies. As initially described, the system would provide total U.S. protection against nuclear attack. The concept of SDI marked a sharp break with the nuclear strategy that had been followed since the development of the armaments race. This strategy was based on the concept of deterrence through the threat of retaliation (see Arms Control). More specifically, the SDI system would have contravened the ABM Treaty of 1972 (see Strategic Arms Limitation Talks). For this reason and others, the SDI proposal was attacked as a further escalation of the armaments race.
Many experts believed the system was impractical. With the dissolution of the Soviet Union, the signing of the START I and II treaties, and the election in 1992 of Bill Clinton as president, the SDI, like many other weapons programs, was given a lower budgetary priority. In 1993 U.S. secretary of defense Les Aspin announced the abandonment of SDI and the establishment of the Ballistic Missile Defense Organization (BMDO) to oversee a less costly program known as National Missile Defense that would make use of ground-based antimissile systems.
The SDI system was originally planned to provide a layered defense employing advanced weapons technologies, several of which were only in a preliminary research stage. The goal was to intercept incoming missiles in midcourse, high above the earth. The weapons required included space- and ground-based nuclear X-ray lasers, subatomic particle beams, and computer-guided projectiles fired by electromagnetic rail guns—all under the central control of a supercomputer system. (The space-based weapons and laser aspects of the system gained it the media name “Star Wars,” after the popular 1977 science-fiction film.) Supporting these weapons would have been a network of space-based sensors and specialized mirrors for directing the laser beams toward targets. Some of these weapons were in development, but others—particularly the laser systems and the supercomputer control—were not certain to be attainable.
The total cost of such a system was estimated at between $100 billion and $1 trillion. Actual expenditures for SDI amounted to about $30 billion. The initial annual budget for BMDO was $3.8 billion.
Cost was not the only controversial issue surrounding SDI. Critics of SDI, including several former government officials, leading scientists, and some NATO members, maintained that the system—even if it had proved workable—could have been outwitted by an enemy in many ways. Also, other nations feared that the SDI system could have been used offensively.
The administration of President George W. Bush gave missile defense a high priority when Bush took office in January 2001. The September 11 terrorist attacks that year gave further impetus to a missile defense system. Secretary of Defense Donald Rumsfeld said such a system was needed to protect the United States from possible attacks by terrorist groups or rogue states. In 2002 the Bush administration withdrew from the ABM Treaty so that it could pursue more vigorous testing of a missile defense program. Criticism of a missile defense system persisted. The Union of Concerned Scientists said the technology did not yet exist to deploy a reliable missile defense system. The group also argued that countermeasures could easily be taken against such a defense system. Other critics noted that terrorists would be unlikely to use missiles and could conceal nuclear weapons, if they obtained them, in a ship or van.

Cruise Missile

Cruise Missile, small pilotless aircraft that carries an explosive warhead. Cruise missiles can be launched from airplanes, trucks, ships, or submarines.
Modern cruise missiles are designed to be reliable and accurate. A typical example is the Lockheed Martin AGM-158 Joint Air-to-Surface Standoff Missile (JASSM). The JASSM weighs 1,000 kg (2,300 lb), has a range of more than 300 km (200 mi), and can be carried on fighter or bomber airplanes.
Cruise missiles resemble airplanes. They have wings and an engine, but they are built somewhat differently to save money. To reduce the cost of the latest cruise missiles, Lockheed Martin engineers borrowed technology from companies that make consumer goods. To make the body, strong fiberglass braids are laid up in a mold. The air is pumped out and hot liquid plastic is pumped in, similar to the construction of a pleasure boat. The wings and tails of the missile are made of fiberglass skins wrapped around plastic foam cores, similar to a surfboard.
Cruise missiles are small and fast but can still be shot down, so designers make them stealthy (hard to detect on radar). To locate a cruise missile, an enemy uses a radar system to transmit radio waves that reflect off the missile or an airplane carrying the missile. The radar receives the reflected signals and thereby determines the speed and position of the cruise missile or the airplane carrying the missile. The stealthy cruise missile or airplane, however, is designed to thwart the radar system. For example, JASSM’s flat sides, pointed nose, and sweptback wings make it hard to detect on radar because any radar signals aimed at the missile bounce away from the radar that sent them out so the radar does not receive back any reflected signals.
A small jet engine powers a cruise missile, typically at speeds of more than 800 km/h (500 mph). The engine is controlled by a computer. In the JASSM, this computer was originally made to control automobile antilock brakes.
A cruise missile is designed to be extremely accurate. It is steered by an inertial navigation system (INS). Used on many airplanes and missiles, an INS measures every movement of the missile and every change of speed, constantly calculating the missile’s position. Any INS “drifts” or loses accuracy over time, like a clock, so current cruise missiles, such as the JASSM, also have a global positioning system (GPS) receiver that corrects the INS with the help of radio signals transmitted by GPS satellites.
Most modern cruise missiles, including the JASSM, have a precision guidance system that allows them to hit small targets. Before a cruise missile is launched, a photograph of the target is loaded into the missile’s computer. As the missile approaches the target, an infrared camera in the nose takes a picture and the computer matches it to the stored image. A cruise missile is so accurate that it can be aimed not just at a building, but at a specific place in the building, such as a door or window.
A cruise missile has a sharp nose and steel casing so that it can penetrate concrete bunkers. Warheads used in the JASSM cruise missile are filled with a type of explosive material that will not blow up if the warhead is dropped accidentally, or even if the airplane carrying the missile catches fire on the ground.
Other cruise missiles include the United States Navy’s Tactical Tomahawk, which is launched from ships and submarines using a rocket booster. A unique feature of this cruise missile is that it can be programmed with up to 15 targets. The missile flies to the first target on its list, and its camera sends a picture back to the ship via radio. If another Tomahawk has already hit the target, the controller can send the missile to its next target.
Some cruise missiles, including the Anglo-French Storm Shadow, use “terrain matching” guidance to help them navigate. Radar measures the height of the ground below the missile and compares these measurements with a three-dimensional map stored in the missile’s computer. Because ground contours are unique, these measurements enable the missile to determine its position.
Primitive “aerial torpedoes” were designed during World War I (1914-1918), but the first practical cruise missile was the German V-1, used in 1944-1945 during World War II. Launched from a catapult, the V-1 was cheap and simple and could carry an 800-kg (1,800-lb) warhead. More than 8,000 V-1s were launched against Britain.
Both the United States and the Union of Soviet Socialist Republics (USSR) built jet-powered, nuclear-armed cruise missiles during the Cold War. The U.S. Air Force’s Northrop Snark, which became the biggest cruise missile ever placed in service when it was activated in 1958, could fly more than 10,000 km (6,000 mi). It was the first aircraft to use INS, and it also had a system that could lock on to stars to correct INS errors. It measured the exact position of Canopus, a visible star, to fix the missile’s position—just as human navigators take star sightings. An even larger missile, the North American Navaho, could cruise at 3,000 km/h (2,000 mph); it was tested but never entered service because the U.S. Air Force bought ballistic rockets instead. The smaller Martin Mace with a range of 2,300 km (1,400 mi) was the first missile with terrain-matching guidance when it went into service in 1959.
The United States retired these weapons in the 1960s, while the Soviet Union continued to build supersonic cruise missiles, designed to attack U.S. aircraft carriers and other large targets.
By the 1970s the development of smaller nuclear warheads, miniaturized electronics, and small, efficient jet engines made it possible to build cruise missiles that were one-sixth the size of Mace. The United States produced thousands of these new missiles, including the Tomahawk, made by General Dynamics (now Raytheon), which could be launched from ships, submarines, or trucks, and the Air-Launched Cruise Missile (ALCM), made by The Boeing Company, which was launched by B-52 bombers.
With the end of the Cold War, the nuclear warheads on many cruise missiles were replaced with explosive warheads. In the Persian Gulf War attacks on Iraq in January 1991, the first weapons launched were ALCMs fired from B-52s—the first cruise missiles fired in battle since 1945. United States Navy surface ships and submarines fired more than 290 Tomahawks at Iraqi targets.
Tomahawks and ALCMs were used in Operation Allied Force, the campaign to remove the Serbian Army from the province of Kosovo in April 1999. For the first time, a non-U.S. force—the British Royal Navy—used Tomahawks as well.
Tomahawks were also used extensively during the 2003 U.S.-British invasion of Iraq to depose the regime of Saddam Hussein. From late March to mid-April more than 800 Tomahawk cruise missiles were fired at Iraqi targets. Fewer than 10 failed to hit their targets, according to the U.S. Navy commander of maritime forces.
To date, cruise missiles have not been a decisive weapon. Military commanders attack most targets by other means. Until the 2003 war in Iraq, cruise missiles were used sparingly because they are expensive. The Tomahawk, for example, costs well over $1 million per missile. Also, in recent wars, enemy forces have not possessed many of the small, important, fixed targets such as permanent missile sites or airplane hangars, that cruise missiles were designed to attack. Another problem is that it is difficult to know whether a cruise missile has destroyed or even hit its intended target because they lack any means of transmitting a target picture back to the launch airplane or ship. New cruise missiles, however, are much cheaper. For example, a JASSM costs under $400,000 and is likely to be more widely used, especially in situations considered too dangerous for piloted aircraft.
The United States and other countries that have developed cruise missiles—including Britain, France, and Russia—have worked to limit the spread of modern cruise missile technology. Exports of long-range missiles are strictly limited, and the United States discourages the sale of weapons in the JASSM class to other countries. For example, the United States has refused to allow F-16 fighters sold to other nations to have such weapons. Experts are concerned, however, that in the long run other nations could use off-the-shelf technology, similar to that used in modern light airplanes, to develop cruise missiles that could pose a serious threat to the big bases and aircraft carriers used by United States and allied forces.


Air Defense Systems

Air Defense Systems, combination of electronic warning networks and military strategies designed to protect a country from a strategic missile or bomber attack. Air defense systems use radar and satellite detection systems to monitor a nation’s airspace, providing data that would allow defense forces to detect and coordinate against such an attack. Several industrialized nations, including the United States, also maintain an arsenal of offensive nuclear weapons as a deterrent to a nuclear attack.
Modern air defense systems originated during World War II (1939-1945) in response to the advent of long-range bomber aircraft. Radar stations in Great Britain were installed to detect approaching German bombers and give British fighter aircraft time to intercept the enemy. Before World War II, most nations focused national defense against assaults from land or sea.
After World War II, the United States enjoyed a brief period of military superiority as the sole possessor of nuclear weapons, but the detonation of an atomic bomb by the Union of Soviet Socialist Republics (USSR) in 1949 brought a new military threat. The United States began to focus its defenses on early detection of long-range bombers, to give U.S. fighter aircraft enough time to respond to a large-scale attack.
The ballistic missile threat was the most important development in air defense systems. When the first German V-2 ballistic missiles arced over England on September 6, 1944, a new day in warfare dawned. The V-2 traveled at supersonic speeds and was impossible to intercept. After World War II an immediate missile race began between the United States and the USSR. The goal was to build upon German technology and create a long-range intercontinental ballistic missile, or ICBM, that could deliver a nuclear warhead.
By 1958 both the United States and the USSR had successfully tested ICBMs and immediately began to improve them. As a result, both nations became extremely vulnerable to attack. The amount of warning that existing national radar systems could provide for an incoming bomber attack had been measured in hours, but an ICBM could loft from a launching base in the USSR and impact in the United States within 30 minutes. There were no technical means to stop a missile once launched, so national leaders turned to the idea of deterrence.
Deterrence uses the threat of an offensive attack as a defense—or deterrent—against such an attack. The USSR, with its initial lead in rocket and missile technology, had adopted a so-called first strike strategy. The Soviet leaders recognized that an exchange of nuclear missiles would be so devastating to both countries that the USSR had to launch its missiles first, and in such numbers that a crippled United States would not be able to mount a significant retaliatory strike. The United States publicly said it would never undertake a first strike, deciding instead to develop a second-strike capability of such magnitude that no Soviet first strike would avoid retaliation. This strategy became known as mutually assured destruction, which had the appropriate acronym MAD. The arms buildup between the United States and the USSR, and the tensions surrounding the buildup, became known as the Cold War because no direct combat took place. Although the world came close to nuclear war on several occasions, such as during the Cuban Missile Crisis, the USSR never dared to launch a first strike, so the United States never had to retaliate.
Defense Systems of Other Countries
Although the Cold War ended in the early 1990s, major military powers continue to employ some version of offensive deterrent and defensive warning capability. Shortly after World War II, political and military alliances were created to offer mutual defense. The United States, Britain, France, and several other countries formed the North Atlantic Treaty Organization (NATO), while the USSR and its satellite countries responded with the Warsaw Pact. Almost all countries monitor their own airspace, but for strategic defense—that is, for protection against nuclear attack—the members of these alliances generally looked to either the United States or the USSR for protection.
Several countries such as the United States, Russia, Britain, France, and China maintain a force of offensive nuclear weapons to deter against a nuclear attack. The offensive capability of the United States rests on what is known as the Nuclear Triad, comprised of strategic bombers, land-based ICBMs, and submarine-launched ballistic missiles. The triad was devised so if any one of the three “legs” is destroyed by an attack, the other two can still function. The nuclear powers of the world maintain some or all of these forces.
From 1945 through about 1960, the United States had depended upon the bomber aircraft of the Strategic Air Command (SAC) to deter an attack from the USSR. In the early years of SAC, these aircraft included the Boeing B-50 and the Consolidated B-36. Later jets such as the Boeing B-47 Stratojet and Boeing B-52 Stratofortress jet bombers were faster and could carry more payload. The United States currently maintains B-52, Rockwell B-1B, and Northrop Grumman B-2 bombers capable of being armed with nuclear weapons as part of its strategic force.
The USSR began an intensive ICBM development program after World War II, and the United States responded in kind. While the Soviet bomber fleet never approached that of the United States in size or capability, the Soviet ICBM fleet was truly formidable. The USSR developed greater numbers of ICBMs than the United States, and these had larger warheads, greater range, and superior accuracy to U.S. weapons. The USSR also was successful in hardening (or making resistant to a nuclear attack) its silo launch facilities to a far greater degree than the United States was able to do.
A similar process followed for the submarine-launched ballistic missile (SLBM), when in the late 1950s the USSR built several submarines able to carry the SS-N-4 Sark missile. In 1960 the United States sent the USS George Washington on patrol, carrying Polaris SLBMs. As technology improved, the SLBM assumed greater importance. A ballistic missile submarine is difficult to detect, can remain on duty for weeks at a time without surfacing, and can fire its missiles from beneath the water’s surface.
Coordination and Command
The U.S. Strategic Command was created to monitor defense information from various sources and coordinate a military response to a nuclear attack. The Strategic Air Command (SAC) was for many years the primary deterrent force. It has been replaced in part by the Air Combat Command. For many years as much as 50 percent of the SAC bomber fleet was on airborne alert, armed with nuclear weapons, and able to attack immediately upon notice.
In the event of an attack, the role of the U.S. Strategic Command was to collect data and present recommendations to the U.S. president and senior advisers (referred to as the National Command Authority). Only the president can make the decision to use nuclear weapons, even in response to an attack. The plan a president would use to respond to an attack is called the Single Integrated Operational Plan, or SIOP. The SIOP consists of several planned responses to various nuclear scenarios. If the U.S. president were to decide to use nuclear weapons, several procedures and code phrases would be used to verify the president’s authority. When the procedures are completed, they would authorize the military to use nuclear weapons. Numerous precautions exist in this process to prevent accidental or unauthorized use of nuclear weapons.
Under SIOP, the president and the rest of the National Command Authority would possibly give orders from a modified Boeing 747 called a National Airborne Operations Center (NAOC). By being airborne, command authority is less vulnerable to a ground attack. These airplanes are outfitted with advanced communications equipment so the president can stay in contact with U.S. Strategic Command at all times. The U.S. Strategic Command also has a number of airborne command centers that can coordinate military forces in the event that ground centers have been destroyed or damaged.
In 2002 the U.S. Strategic Command was merged with the U.S. Space Command. The role of the Space Command had been to monitor a global network of satellites and ground sensors that warn of missile launchings. The purpose of the merger was to create a single command responsible for both early warning against an attack and for responding to such an attack or for initiating an attack. The merger was seen as a step in implementing a new policy, outlined by President George W. Bush, of preemptive, or first-strike, attacks against nations that develop weapons of mass destruction, including biological and chemical weapons.
The consequences of a nuclear exchange would be devastating, with casualties estimated to be in the hundreds of millions on both sides and massive damage to the environment. Both the USSR and the United States were aware of the catastrophic scale of a nuclear exchange, and both built elaborate defensive systems to detect an incoming nuclear attack.
Radar Networks
From 1949 (when the USSR developed nuclear weapons) to 1959 (when ICBMs became operational), the main strategic threat was bombers. To provide advance warning, several radar posts were built across Canada by joint cooperation between Canada and the United States. The first series of linked radar stations was called the Pinetree Line, established in 1954. Two more lines, the Mid-Canada Line and the Distant Early Warning Line (or DEW Line), were created for more complete radar coverage. The DEW Line, comprising 60 radar sites along the 70th parallel, became operational in 1957.
To warn against ICBMs, the Ballistic Missile Early Warning System (BMEWS) was introduced in 1962. It consisted of sophisticated radar sites in Greenland, Alaska, and England. These sites could detect, track, and predict impact points of both intercontinental ballistic missiles and smaller intermediate range ballistic missiles (IRBMs) launched from within the USSR. A typical site has four giant scanner search radars, each 50.3 m (165 ft) high and 122 m (400 ft) long, and one tracking radar, a 25.6 m (84 ft) antenna in a 42.6 m (140 ft) diameter housing. The purpose of the BMEWS is to provide sufficient warning time for U.S. bombers to get airborne and ICBM forces to prepare for a counterstrike.
The BMEWS was backed up by the Perimeter Acquisition Radar Characterization (PARCS) system. Operating in the U.S. interior, PARCS can detect air traffic over Canada. Four other radar sites monitor the Atlantic and Pacific oceans for possible submarine attacks. These various stations were connected to the North American Aerospace Defense Command (NORAD), to U.S. Strategic Command headquarters, the Pentagon, and to the Canadian Royal Air Force fighter command.
NORAD was activated in 1957 to provide an integrated command for the air defense of the United States and Canada, and to process the information gathered from various radar sites. The reality of ICBMs required the establishment of a detection and tracking system, and the housing of NORAD in a bombproof site located within the interior of Cheyenne Mountain near Colorado Springs, Colorado. With its increased responsibility, NORAD equipment was expanded to include the Airborne Warning and Control Aircraft (AWACS), Over the Horizon (OTH) radar that warns against low-altitude cruise missiles, and a network of satellites. The DEW Line was replaced with a superior system called the North Warning System, and the Joint Surveillance System (JSS), operated by the U.S. Air Force and the Federal Aviation Administration, provides additional air traffic coverage. NORAD was later renamed the U.S. Space Command. As a result of the 2002 merger between the Space Command and the Strategic Command, the joint Space Command/Strategic Command monitors all of these early warning systems.
Soviet Air Defense
The USSR built an even more extensive integrated air defense system, covering the country with radar systems, surface-to-air missile sites, and large numbers of interceptors (fast military aircraft designed to destroy attacking airplanes). The USSR built a huge infrastructure of civil and military defense systems, including deep underground blast shelters for the country’s leaders and key industries. Following the breakup of the USSR in 1991, only a remnant of this civil defense network remained in Russia. The United States abandoned its rather primitive civil defense efforts of the 1950s and has not replaced it with any other system.
Antiballistic Missile Systems
Active defense systems have been proposed that would use interceptor missiles to track and shoot down incoming ICBMs detected and tracked by radar. These are known as antiballistic missile (ABM) or ballistic-missile defense (BMD) systems. The most important U.S. antiballistic missile systems were the 1967 “Sentinel,” the 1969 “Safeguard,” and the Strategic Defense Initiative (SDI), which was proposed by U.S. president Ronald Reagan in 1983. SDI would have used a combination of satellite-based sensors and weapons to destroy ballistic missiles after their launch. The research that began on SDI continued in various ways, but no actual program was started because costs were deemed too high.
The 1972 Anti-Ballistic Missile (ABM) Treaty signed by the United States and the USSR limited the implementation of antiballistic missile systems. Russia developed one system around Moscow, and this system still exists although it is very old. The United States had a system in North Dakota but closed it down due to cost and reliability issues. However, in 2001 the administration of United States president George W. Bush announced that it was unilaterally withdrawing from the ABM Treaty. Bush called for the creation of a rudimentary missile defense system by 2004. Some critics of the decision called it destabilizing because other nations could interpret it as a move by the United States toward a first-strike strategy. Other critics of the decision focused on the problematic costs and reliability of ABM systems. See also Arms Control.
Another defensive system against missile attacks is the Patriot missile, which is designed to destroy shorter-range ballistic missiles, such as the Scud missiles used by Iraq during the 1991 Persian Gulf War. Patriot missiles were also used by U.S. forces during the 2003 invasion of Iraq. The United States also indirectly defends against some missiles through the antisubmarine warfare combination of undersea surveillance and the use of attack submarines and surface ships to track Russian ballistic missile submarines. While none of these weapons can intercept an enemy missile once launched, they can track and destroy the submarine itself.
With the end of the Cold War between the former Soviet Union and the United States, the threat of an all-out nuclear attack has greatly diminished. It is highly unlikely that Russia would ever launch a massive first strike against the United States, and both countries have significantly reduced their nuclear forces. Under the terms of an arms reduction treaty signed in 2002 between the United States and Russia, both nations agreed to reduce their strategic nuclear arsenals to about 2,200 nuclear warheads by the year 2012. Still, the threat of nuclear war remains because of the spread of nuclear weapons. In 1998 India and Pakistan conducted nuclear bomb tests. In 2003 North Korea told U.S. officials that it possessed nuclear weapons. Only five nations have openly revealed the number of nuclear weapons they possess. They are China, France, Russia, the United Kingdom, and the United States. As of 2002, the number of nuclear weapons each nation possessed was China (434), France (482), Russia (about 6,000), the United Kingdom (200), and the United States (about 6,000). Israel is known to have the capability to deploy some 100 nuclear weapons. See also Strategic Arms Limitation Talks, Arms Control.


Sarin, nerve agent used in chemical warfare; its chemical name is isopropyl methyl phosphonofluoridate. A colorless liquid that gives off no odor as it vaporizes, sarin is a highly toxic compound in both its liquid and vapor state. It attacks the central nervous system, causing death minutes after exposure. Sarin dissipates quickly so its persistence in the environment is low; it can be made more persistent through the addition of certain oils or petroleum products. Delivery systems include ballistic and cruise missiles, crude canisters, aircraft-delivered bombs, artillery shells, and land mines. The organophosphate nerve agents tabun, sarin, soman, and cyclosarin are among the most toxic chemical warfare agents known. See also Chemical and Biological Warfare.
Sarin was developed in Nazi Germany in 1938. Its name is derived from the names of its inventors: Schrader, Ambrose, R├╝diger, and van der Linde. The North Atlantic Treaty Organization (NATO) adopted it as a standard chemical warfare agent in the early 1950s. Iran, North Korea, Syria, and possibly Libya are believed to hold stocks of sarin. Iraq used it in the Iran-Iraq War (1980-1988) and had large stocks available during the Persian Gulf War (1991). The Japanese Aum Shinrikyo religious sect used sarin in the only known terrorist acts involving a chemical weapon. The sect released sarin in Matsumoto, Japan, in 1994, killing 7 people, and on the Tokyo subway in 1995, killing 12 and injuring 5,500.
Like other nerve agents, sarin kills by paralyzing muscles so that a person cannot breathe. It also affects glands that control tears, sweat, and other body secretions. Sarin enters the body by inhalation, ingestion, and through the eyes and skin. Symptoms begin with watery eyes, drooling, and excessive sweating, and then rapidly progress to difficulty in breathing, dimness of vision, nausea, vomiting, twitching, and headache. Ultimately the victim will become comatose and suffocate as a consequence of convulsive spasms. Immediate treatment is decontamination by removing clothing and flushing eyes and skin with water.