Since the end of the Cold War, the concept and pursuit of America's national security have undergone numerous revisions. The threat of state-led nuclear proliferation remains; yet this danger is now paralleled, even surpassed, by cyber warfare's direct challenge to the nation's commerce, infrastructure, and electoral system. Terrorist threats presented by violent non-state actors may not pose an existential threat to the US, but they are nevertheless capable of inflicting tremendous damage and loss of life. This panel will discuss the internal and external dimensions of national security in 2020, focusing on how critical it is for US military, civilian, and governmental entities to coordinate their efforts in the face of these continued and emerging threats.