<Li> Ballistic Missile Defense Organization Missile Defense Agency </Li> <Tr> <Th> Jurisdiction </Th> <Td> Federal government of the United States </Td> </Tr> <P> 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 . </P> <P> 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 . A number of these concepts were tested through the late 1980s, and follow - on efforts and spin - offs continue to this day . </P>

What was the main goal of the strategic defense initiative