Strategic Defense Initiative

The Strategic Defense Initiative (SDI) was a proposed missile defense system intended to protect the United States from attack by ballistic strategic nuclear weapons (intercontinental ballistic missiles and submarine-launched ballistic missiles). The concept was first announced publicly by President Ronald Reagan on 23 March 1983. Reagan was a vocal critic of the doctrine of mutual assured destruction (MAD), which he described as a 'suicide pact', and he called upon the scientists and engineers of the United States to develop a system that would render nuclear weapons obsolete. The Strategic Defense Initiative Organization (SDIO) was set up in 1984 within the United States Department of Defense to oversee development. A wide array of advanced weapon concepts, including lasers, particle beam weapons and ground- and space-based missile systems were studied, along with various sensor, command and control, and high-performance computer systems that would be needed to control a system consisting of hundreds of combat centers and satellites spanning the entire globe and involved in a battle that would last only minutes. A number of these concepts were tested through the late 1980s, and follow-on efforts and spin-offs continue to this day. Under the SDIO's Innovative Sciences and Technology Office, headed by physicist and engineer Dr. James Ionson, the investment was predominantly made in basic research at national laboratories, universities, and in industry; these programs have continued to be key sources of funding for top research scientists in the fields of high-energy physics, supercomputing/computation, advanced materials, and many other critical science and engineering disciplines — funding which indirectly supports other research work by top scientists, and which would be politically impossible to fund outside of the defense budget environment. In 1987, the American Physical Society concluded that the technologies being considered were decades away from being ready for use, and at least another decade of research was required to know whether such a system was even possible. After the publication of the APS report, SDIs budget was repeatedly cut. By the late 1980s, the effort had been re-focused on the 'Brilliant Pebbles' concept using small orbiting missiles not unlike a conventional air-to-air missile, which was expected to be much less expensive to develop and deploy. SDI was controversial throughout its history, and was criticized for threatening to destabilize the MAD-approach and to possibly re-ignite 'an offensive arms race'. SDI was derisively nicknamed by Democratic Senator Ted Kennedy as 'Star Wars', after the 1977 film by George Lucas. By the early 1990s, with the Cold War ending and nuclear arsenals being rapidly reduced, political support for SDI collapsed. SDI officially ended in 1993, when the administration of President Bill Clinton redirected the efforts towards theatre ballistic missiles and renamed the agency the Ballistic Missile Defense Organization (BMDO). BMDO was renamed the Missile Defense Agency in 2002. The US Army had considered the issue of ballistic missile defense (BMD) as early as late in World War II. Studies on the topic suggested attacking a V-2 rocket would be difficult because the flight time was so short that it would leave little time to forward information through command and control networks to the missile batteries that would attack them. Bell Labs pointed out that although longer-range missiles flew much faster, their longer flight times would address the timing issue and their very high altitudes would make long-range detection by radar easier. This led to a series of projects including Nike Zeus, Nike-X, Sentinel and ultimately the Safeguard Program, all aimed at deploying a nationwide defensive system against attacks by Soviet ICBMs. The reason for so many programs was the rapidly changing strategic threat; the Soviets claimed to be producing missiles 'like sausages', and ever-more missiles would be needed to defend against this growing fleet. Low-cost countermeasures like radar decoys required additional interceptors to counter. An early estimate suggested one would have to spend $20 on defense for every $1 the Soviets spent on offense. The addition of MIRV in the late 1960s further upset the balance in favor of offense systems. This cost-exchange ratio was so favorable that it appeared the only thing building a defense would do would be to cause an arms race. When initially faced with this problem, President Eisenhower asked ARPA to consider alternative concepts. Their Project Defender studied all sorts of systems, before abandoning most of them to concentrate on Project BAMBI. BAMBI used a series of satellites carrying interceptor missiles that would attack the Soviet ICBMs shortly after launch. This boost phase intercept rendered MIRV impotent; a successful attack would destroy all of the warheads. Unfortunately, the operational cost of such a system would be enormous, and the US Air Force continually rejected such concepts. Development was cancelled in 1963.