America is immersed in cyberspace. Government, private enterprise and most individual American citizens enjoy the benefits and efficiencies of cyberspace. Wealth, intellectual property and reputation are just a small sample of the individual and collective riches that can reside within it. In fact, most average Americans would struggle to remember living without some of its conveniences. This phenomenon is not unique to America; it is pervasive around the world, among allies and adversaries of the United States alike. Innovation continues to expand the reach and utility of cyberspace, while also introducing new vulnerabilities.National security experts remain bitterly divided about the role and importance of cyberspace in the next conflict. Some even fear there could be a cyber-Armageddon event looming just over the horizon. The nature of competition in cyberspace advances generates legitimate concerns that the United States may not always be prepared for a cyber “unknown-unknown,” an undetectable advancement that provides others with an asymmetric cyber advantage. Cyberspace is like a game of global chess, wherein the players are unsure who else is playing, uncertain of friend or foe, unclear about the terrain and unconvinced the players will act according to established norms and rules. Uncertainty in cyberspace makes it difficult to assess risk, which is determined by the probability of an event and the severity of its outcome.Despite the lack of consensus on cyber risk, few can disagree that cyberspace has already become a hotly contested domain that will play a prominent role in the next conflict. Military operations in cyberspace offer great opportunities while simultaneously posing significant challenges. These potential vulnerabilities demand that the United States military continue to build a world-class cyber force.