In today's global environment States are increasingly reliant on cyberspace for everything from banking services to infrastructure management. While this environment provides many benefits, reliance on digital systems also leaves us vulnerable. Malicious actions in cyberspace raise multiple legal and ethical questions for States wishing to respond to, or prevent, such actions. The Just War Framework provides an organized way to determine whether the reasons for going to war and the conduct of the war itself are morally justified; however, the international community has not yet adapted laws and international norms to cyberspace. Many questions remain regarding what actions rise to the threshold of armed attack, when a State has an inherent right to self-defense, and how to approach the problem of attribution for cyber attacks. The international community is seeking to clarify norms, most notably through NATO's Cooperative Cyber Defence Centre of Excellence, which published the Tallinn Manual in 2013. The United States must continue to participate in these and other forums and continue to partner with like-minded actors who share our goals of an open and secure cyberspace.