 The Strategic Defense Initiative was created by U.S. President Ronald Reagan on March 23, 1983 to use ground and space-based systems to protect the United States from attack by strategic nuclear ballistic missiles.Supporters of SDI claimed it helped contribute to the fall of the Soviet Union by the so-called strategy of technology, which was a prevalent doctrine at the time.While SDI was a source of disagreement between the United States and the Soviet Union a summit led to the Intermediate-Range Nuclear Forces Treaty, which some have claimed was an outgrowth of USSR's Mikhail Gorbachev's fear of SDI.