Short answers, pulled from the story.
President Ronald Reagan announced the Strategic Defense Initiative on the 23rd of March 1983. This declaration was made before a national television audience where he called for creating a shield against ballistic missiles.
The Strategic Defense Initiative developed directed-energy weapons including particle-beam systems, X-ray lasers like Excalibur, and kinetic kill vehicles such as Brilliant Pebbles. The program also tested railgun technology and neutral particle beam accelerators to intercept incoming ICBMs at high speeds.
Critics argued the Strategic Defense Initiative was unfeasible because existing systems required energy output improvements of up to one million times to be effective. Physicists Hans Bethe and Richard Garwin stated the defensive system would be costly yet simple to destroy using thousands of decoys.
The Soviet Union responded to the Strategic Defense Initiative by threatening various military countermeasures instead of developing parallel missile defense systems. They launched the Polyus satellite in 1987 which housed Skif lasers intended for clandestine testing but failed to reach orbit due to attitude control malfunction.
The Clinton administration renamed the Strategic Defense Initiative Organization to the Ballistic Missile Defense Organization BMDO in 1993. This shift focused ground-based interceptor missiles on theater-scale systems under programs like ERINT and FLAGE.