<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 ( 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>
what was the main goal of the strategic defense initiative
what was the main goal of the strategic defense initiative
to protect the United States from attack by ballistic strategic nuclear weapons ( intercontinental ballistic missiles and submarine - launched ballistic missiles )
to protect the United States from attack by ballistic strategic nuclear weapons ( intercontinental ballistic missiles and submarine - launched ballistic missiles )