The defense industry develops, produces, and sells weapons that cause great harm. It operates at the intersection of the public and private sectors, with increased reliance on technology companies. Although such firms exist primarily to serve their host states, they routinely interact with foreign legal systems and diverse cultures. This context creates unique ethical challenges. That being the case, is the defense industry ethically defensible? How should it be regulated? How should it respond to worrisome technological developments such as autonomous weapons systems? How should business be conducted in countries where bribery is the norm? To what extent can this industry's intrinsic ethical problems be overcome? This book addresses such questions, bringing together the diverse perspectives of scholars and practitioners from academia, government service, the military, and the private sector. It aims to inform a discussion about the moral and legal challenges facing the global defense industry and to introduce solutions that are innovative, effective, and practical.