Which act focuses on internal security for military installations?

The Internal Security Act of 1950 is specifically designed to address issues of internal security within the United States, focusing particularly on military installations. This act was enacted during the Cold War, reflecting the government's concern about subversive activities and the potential threat posed by communist influence. It provided measures to strengthen security within military and defense contexts, ensuring that military installations are safeguarded from espionage and other activities that could compromise national security.

In contrast to other options, the Homeland Security Act primarily addresses broader national security concerns following the events of September 11, 2001. The Defense Authorization Act mainly focuses on the budget and expenditures for the Department of Defense, while the National Security Act covers a broader scope of foreign and domestic policies and national defense, without the specific focus on internal security for military installations that the Internal Security Act provides. Thus, the correct response directly ties to the original intent and provisions set forth to enhance security at military bases and related installations.