From North Korea's recent attacks on Sony to perpetual news reports of successful hackings and criminal theft, cyber conflict has emerged as a major topic of public concern. Yet even as attacks on military, civilian, and commercial targets have escalated, there is not yet a clear set of ethical guidelines that apply to cyber warfare. Indeed, like terrorism, cyber warfare is commonly believed to be a war without rules. Given the prevalence cyber warfare, developing a practical moral code for this new form of conflict is more important than ever. In Ethics and Cyber Warfare, internationally-respected ethicist George Lucas delves into the confounding realm of cyber conflict. Comparing "state-sponsored hacktivism" to the transformative impact of "irregular warfare" in conventional armed conflict, Lucas offers a critique of legal approaches to governance, and outlines a new approach to ethics and "just war" reasoning. Lucas draws upon the political philosophies of Alasdair MacIntyre, John Rawls, and Jürgen Habermas to provide a framework for understanding these newly-emerging standards for cyber conflict, and ultimately presents a professional code of ethics for a new generation of "cyber warriors." Lucas concludes with a discussion of whether preemptive self-defense efforts - such as the massive government surveillance programs revealed by Edward Snowden - can ever be justified, addressing controversial topics such as privacy, anonymity, and public trust. Well-reasoned and timely, Ethics and Cyber Warfare is a must-read for anyone with an interest in philosophy, ethics, or cybercrime.