The official mission of the Marine Corps is established in which act?

The official mission of the Marine Corps is outlined in the National Security Act of 1947, which was amended in 1952. This act is significant because it codifies the roles and responsibilities of the Marine Corps within the broader context of national defense and military organization. It emphasizes the importance of the Marine Corps in providing a rapid response capability and maintaining readiness for land and amphibious operations as part of the armed forces of the United States.

The act created a framework for the organization of the U.S. military, including the establishment of the Department of Defense and the coordination between the different branches of the military. By setting forth the mission of the Marine Corps in this act, it ensures that the Corps operates under a clear legal foundation that defines its purpose, aligns its operations with national defense objectives, and affirms its unique role as a rapid, versatile force able to engage in a variety of tasks.

The other choices reference important legislation related to military operations and legal frameworks but do not specifically define the mission of the Marine Corps as directly as the National Security Act of 1947 does.