Final answer:
The acronym SDI refers to the Strategic Defense Initiative, illustrating the US's commitment to defense, particularly during the Cold War. This broader strategy included reshaping military organizations and educating the public. SDI symbolizes the historical era's significant focus on national security infrastructure and emergency preparedness.
Step-by-step explanation:
The acronym that identifies the priorities in establishing a defense, specifically within the context of US history post-World War II, is SDI, which stands for the Strategic Defense Initiative. The SDI was a program initiated during the Cold War to develop a sophisticated anti-ballistic missile system that was intended to protect the United States from nuclear attacks.
This initiative reflects a broader strategy of national defense that encompasses implementing civil defense and emergency preparedness measures, which also includes anti-terrorism legislation, and ensuring the resilience of critical national infrastructure.
As part of this defense strategy, other significant changes occurred. The National Security Act of 1947 reorganized the U.S. military and created the National Security Council and the CIA to coordinate defense policies and intelligence efforts.
Subsequently, the Department of Defense was formed by combining the Departments of the Army, Navy, and Air Force. Additionally, public measures were taken to inform and prepare the citizenry, such as the Alert America campaign and educational materials provided to schools.