[20201229]IF10541_防务基础：弹道导弹防御系统.pdf

https:/crsreports.congress.gov Updated December 29, 2020Defense Primer: Ballistic Missile DefenseThe United States has been developing and deploying ballistic missile defenses (BMD) to defend against enemy missiles continuously since the late 1940s. In the late 1960s and early 1970s, the United States deployed a limited nuclear-tipped BMD system to protect a portion of its U.S. land-based nuclear ICBM (intercontinental ballistic missile) force in order to preserve a strategic deterrent against a Soviet nuclear attack on the Homeland. That system became active in 1975 but shut down in 1976 because of concerns over cost and effectiveness. In the FY1975 budget, the Army began funding research into hit-to-kill or kinetic energy interceptors as an alternativethe type of interceptor technology dominates U.S. BMD systems today. In 1983, President Reagan announced an enhanced effort for BMD. Since the start of the Reagan initiative in 1985, BMD has been a key national security interest in Congress. It has appropriated well over $200 billion for a broad range of research and development programs and deployment of BMD systems here and abroad. The Missile Defense Agency (MDA) is charged with