The aerospace industry has long been protected and promoted by governments for reasons of national security. In recent decades, however, growing development costs and the importance of scale economies in aircraft production have combined with the dispersion of leadership in component technologies to drive U.S. aerospace companies to adopt a global approach to the development and production of both military and civilian aircraft and engines. What are the implications of the globalization of the aerospace industry for the national security of major industrial states, including the United States, during a period in which bipolar Cold War tensions have all but vanished?