Adversary cyberspace capabilities threaten the United States military and national security interests across all levels of conflict. Despite these threats, within the United States military and senior civilian leadership there exists limited knowledge on cyberspace beyond rudimentary user-level understanding. This project serves as a primer to help fill the educational gap of strategic military leaders on the attributes and issues of cyberspace relevant to modern national security. It will accomplish this task by reviewing cyberspace’s evolution, the legal issues surrounding the application of international law of armed conflict, and the ways and means of conducting offensive and defensive cyberspace operations. The discussion will conclude by developing a framework based on the variables of attribution, attacker identity, target criticality, and attack severity to provide the strategic military leader with a conceptual model for development of a whole-of-government response to adversaries who threaten the United States through cyberspace.