Final answer:
President Ronald Reagan proposed the Strategic Defense Initiative on 23 March to replace mutually assured destruction with assured survival.
Step-by-step explanation:
On 23 March, President Ronald Reagan proposed replacing the doctrine of mutually assured destruction with one of assured survival, known as the Strategic Defense Initiative (SDI), to intercept ICBMs.
Reagan aimed to redefine the Cold War paradigm by advocating for assured survival through advanced missile defense systems capable of intercepting intercontinental ballistic missiles (ICBMs). Commonly dubbed "Star Wars," SDI envisioned space-based technologies like lasers and missile interceptors to protect the United States from nuclear threats.
Though the initiative faced technical challenges and criticisms, it ignited debates on global security strategies. Reagan's proposal reflected a visionary departure from traditional deterrence policies, emphasizing proactive defense measures and contributing to discussions that ultimately influenced later missile defense programs and arms control negotiations.