The Department of Defense (DOD), Department of Energy’s National Nuclear Security Administration (NNSA), and national defense laboratories are significantly invested in materials research explicitly for national security. While DOD uses advanced materials to help protect and arm American troops, and NNSA uses advanced materials to ensure the safety and effectiveness of the American nuclear weapons deterrent, materials also play a role in many other areas of national security. Materials advances are important for lighter-weight protection systems and vehicles, advanced energetic materials, composites used in turbine engines, lifetime prediction of defense systems, electronics, and energy storage and distribution, among other applications. Many important materials developments eventually are transitioned into commercial products that enhance the well-being of the country at large.