The Aspen Strategy Group convened its 2013 Summer Workshop on “The Future of American Defense”, a timely series of discussions that examined U.S. defense strategy in a time of budgetary constraints, political impasse, and a changing geopolitical landscape. The workshop opened with the Ernest R. May Memorial Lecture entitled “Austerity and U.S. Strategy: Lessons of the Past,” on the ways limited defense resources have sometimes encouraged creative thinking over time. Informed by this historical perspective, the discussions took a broad look at defense posture in a post-9/11 world. Following a debate on the aims and objectives of U.S. defense strategy, the group turned its attention on how to direct our increasingly limited resources to support a future defense strategy that maintains our nation’s readiness and technological advantage. The group also discussed the role that traditional allies can play, especially as the U.S. rebalances towards Asia and as current events in the Middle East continue to draw our attention. Members of the Aspen Strategy Group and outside experts sought to produce the framework for a sound defense strategy that meets our commitments, while being both efficient and effective. Papers presented at this meeting were compiled and published in February 2014 as a policy book, which can be purchased through the Aspen Institute Press here or through our partner, the Brookings Institution Press here.