Strategic Defense Initiative (SDI)
The Strategic Defense Initiative (SDI) was a proposed missile defense system announced by U.S. President Ronald Reagan on March 23, 1983, during the Cold War. It aimed to create a comprehensive defensive shield to protect the United States from nuclear missile attacks, particularly from the Soviet Union. The initiative envisioned a multi-layered defense system that included space-based satellites to intercept missiles in various stages of flight, potentially utilizing advanced technologies such as lasers and other directed-energy weapons.
Despite its ambitious goals, SDI faced significant criticism and skepticism regarding its technological feasibility, with opponents arguing that it could escalate arms competition rather than reduce nuclear threats. Critics also expressed concerns about the potential violation of the 1972 Anti-Ballistic Missile Treaty, which limited missile defense systems to prevent an arms race. While the program received around $30 billion in funding throughout the 1980s, its relevance diminished after the collapse of the Soviet Union. Subsequent administrations shifted the focus of missile defense research towards regional threats rather than global deterrence, leading to the formation of the Ballistic Missile Defense Organization in 1993. The legacy of SDI remains a topic of debate in discussions about national defense and arms control.
Strategic Defense Initiative (SDI)
Identification Plan to establish an antiballistic missile defense
In an effort to protect the United States from a possible nuclear attack by the Soviet Union, President Ronald Reagan proposed a high-tech defense shield capable of shooting down incoming Soviet missiles. The plan generated much criticism, both of its technical infeasibility and of its political ramifications.
In the 1970’s, the United States followed a nuclear deterrence strategy known as mutually assured destruction (MAD), which depended on a situation in which the United States and the Soviet Union each possessed enough nuclear weapons to survive an attack by the other and still launch a devastating counterstrike. The certainty of utter annihilation in a nuclear war thus prevented one from happening. When Ronald Reagan became president, however, he considered MAD a risky strategy, especially as the number of Soviet nuclear warheads increased. After consultations with scientific advisers, Reagan gave a nationally televised speech on March 23, 1983, in which he announced plans to establish the Strategic Defense Initiative (SDI), which was tasked with creating a defensive shield to protect the United States from nuclear attack. Reagan’s televised proposal envisioned a space-based front line of satellite defenses that could destroy Soviet missiles at the early-launch stage, a space-based second line to destroy individual warheads released by Soviet missiles that got through the front line, and a ground-based third line to destroy any warheads in their terminal phase that avoided the other defensive lines.
Pushing the Technical Boundaries
Shooting down Soviet missiles represented a huge technical challenge. The project started with ground-based missile technology, such as the Extended Range Interceptor (ERINT), originally developed for the Safeguard Anti-Ballistic Missile system devised in the 1970’s. The Strategic Defense Initiative Organization(SDIO), established at the Pentagon in 1984, funded a number of innovative approaches based on the ERINT technology that sought to detect, target, and destroy Soviet missiles. On the relatively low-tech end of development were projects like the Homing Overlay Experiment, a missile-launched projectile with four-meter-diameter fans to increase the size of the projectile and ensure a hit, and Brilliant Pebbles, watermelon-sized satellites that would destroy Soviet missiles by purposely colliding with them.
On the high-tech end of the research spectrum were a number of directed-energy weapons programs that used energy to destroy missiles, rather than physical collisions between missiles and targeting projectiles. These high-tech projects, centered on beam-projecting weaponry, earned SDI its skeptical nickname, “Star Wars.” The first research centered on an X-ray laser powered by a nuclear explosion, with first tests carried out in 1983. In 1985, the SDIO began tests with a deuterium fluoride laser, which successfully destroyed a Titan missile booster and several low-flying target drones. Another promising project was the Hypervelocity Rail Gun, a space-based platform that destroyed satellites with “bullets” fired at fourteen hundred miles per hour. The main drawback of the fluoride laser and the Rail Gun was the massive electricity requirement of the systems. Experiments on sensors designed to detect and target incoming Soviet warheads, such as the Boost Surveillance and Tracking System, proved much more successful, as they proved capable of tracking Soviet missiles from their initial launches through their entire flight path. The total of SDI funding amounted to approximately $30 billion between 1983 and 1989.
Criticism of SDI
While many Americans supported SDI, the plan attracted a considerable amount of criticism. Some critics believed the system to be so far beyond the technical capability of current science that it would remain unfeasible for the foreseeable future. They therefore argued that it represented a massive waste of resources. Others saw SDI as a waste of resources even if it worked, because it diverted funds from other government programs that should receive a higher priority. Some foreign-policy critics saw SDI as an open provocation to the Soviets that might trigger a new arms race.
Antiwar advocates postulated that SDI actually increased the chance of a nuclear war. They feared that the United States, safe behind its SDI shield, might be more inclined to launch a nuclear attack on the Soviet Union, because the Soviets would not be able to inflict similar damage in a counterstrike. It also seemed possible that the Soviet Union might consider launching a preemptive attack against the United States before SDI became operational and Soviet nuclear weapons became useless. Another major criticism of SDI was its potential violation of the 1972 Anti-Ballistic Missile (ABM) Treaty, which placed limitations on American and Soviet missile defense systems. Supporters of SDI claimed that the ABM Treaty applied only to ground-based systems and not to the space-based systems envisioned by President Reagan.
Impact
Research continued on SDI throughout the 1980’s. With the fall of the Soviet Union, however, the project lost much of its purpose. Many pro-Reagan analysts claim that SDI helped bankrupt the communist system, as the Soviets were forced to spend money they could not afford on technology designed to match or overcome the initiative.
Subsequent Events
Later presidents continued antiballistic missile research, but for regional defense against missiles launched by terrorist groups or rouge nations. In 1993, President Bill Clinton renamed SDIO the Ballistic Missile Defense Organization (MBDO), reflecting its reduced mission from global to regional defense. Even this more modest program remained controversial, however, because it continued to violate the ABM Treaty and was accused by critics of potentially provoking a new Cold War-style arms race.
Bibliography
Guertner, Gary L., and Donald M. Snow. The Last Frontier: An Analysis of the Strategic Defense Initiative. Lexington, Mass.: Lexington Books, 1986. Examination of the scientific and political ramifications of the project.
Linenthal, Edward. Symbolic Defense: The Cultural Significance of the Strategic Defense Initiative. Urbana: University of Illinois Press, 1989. Discussion of how America and the rest of the world perceived SDI and reacted to the project’s expectations and implications.
Reiss, Edward. The Strategic Defense Initiative. Cambridge, England: Cambridge University Press, 2003. Well-documented history of SDI and its impact, with analysis of subsequent projects beyond the 1980’s.