Presidents Ronald Reagan and George W. Bush both promoted the development of a system to defend the United States against attack by enemies from outer space. What is the name of this initiative?

During the Cold War, the concept of a space-based defense system emerged as a highly ambitious initiative to protect the United States from ballistic missile attacks. This program, officially known as the Strategic Defense Initiative (SDI), was announced by President Ronald Reagan in 1983. Its goal was to create a multi-layered shield that could intercept and destroy incoming nuclear missiles, potentially using advanced technologies like lasers and particle beams, both from land and space. The media quickly dubbed it the "Star Wars" defense, a nickname that stuck due to the futuristic and seemingly science-fiction nature of its proposals, reminiscent of the popular movie franchise.

President Reagan saw SDI as a way to move beyond the doctrine of Mutually Assured Destruction (MAD), which he viewed as a "suicide pact" that relied on the threat of devastating retaliation to prevent nuclear war. He believed a defensive shield could render nuclear weapons obsolete and fundamentally change the dynamics of the Cold War. The initiative sparked considerable debate and controversy, with critics questioning its technological feasibility, its immense cost, and the potential for it to escalate the arms race rather than reduce nuclear threats. Despite these challenges, billions of dollars were invested in research and development throughout the 1980s.

While SDI was never fully deployed in its original form, the research conducted under the program contributed to advancements in various technologies, including satellite surveillance and communications. Following the Cold War, the focus of missile defense shifted, but the idea of protecting against missile threats persisted. President George W. Bush, in the early 2000s, also championed robust missile defense programs, emphasizing the need for a layered system to defend the U.S. against potential attacks, particularly from rogue states. His administration increased spending on missile defense and controversially withdrew the U.S. from the Anti-Ballistic Missile (ABM) Treaty to pursue these goals, highlighting a continued commitment to the defensive principles first articulated by Reagan's Strategic Defense Initiative.