Final answer:
The Strategic Defense Initiative (SDI), also known as "Star Wars," was never fully implemented due to skepticism about the technology, fears of worsening the arms race, and concerns about the cost.
Step-by-step explanation:
The Strategic Defense Initiative (SDI), also known as "Star Wars," was never fully implemented due to a combination of factors. One reason was the skepticism and doubts about the feasibility of the technology involved. Critics pointed out that the system would have to be able to shoot down multiple missiles simultaneously to be effective, a challenge considering the limitations of existing technology.
Another factor was the fear of worsening the arms race with the Soviet Union. The Soviet leaders saw SDI as a potential threat to their nuclear deterrence strategy and believed it could upset the strategic balance. They feared that if the United States successfully developed the system, they would be vulnerable to a nuclear attack without the fear of retaliation. Lastly, there were concerns about the cost of implementing SDI and the impact it would have on the nation's budget. The estimated cost of the plan was around $7.5 billion, and critics argued that this money could be better spent on other defense priorities.