This bill reorganizes the Department of Defense's leadership structure for industrial base and homeland defense matters. It creates a new Assistant Secretary of Defense for International Industrial Base Development and Engagement, whose main job is to strengthen U.S. defense manufacturing by working with allied nations including Taiwan. The bill also renames the Assistant Secretary of Defense for Strategy, Plans, and Capabilities to add "Homeland Defense" to the title, expanding that position's duties to include advising top defense officials on homeland defense, disaster support, Arctic resilience, and coordination with federal agencies, states, and private companies. To streamline the organization, the bill eliminates the existing Assistant Secretary of Defense for Homeland Defense and Hemispheric Affairs position and transfers Western Hemisphere responsibilities to the Assistant Secretary of Defense for International Security Affairs. The legislation contains no specific funding amounts or implementation timelines beyond taking effect upon enactment.