This paper discusses the current circumstances of security in cyberspace, such as cyber armies and cyber intelligence. Cyber intelligence plays a vital role in the balance of power. Most importantly, this paper explores previous studies of the International Relations (IR) theory of Realism. Cybersecurity can be applied as the equivalent of a nuclear deterrent of Realism and is inspired by the sense of the threat that allied countries felt in regard to cybersecurity. Countries utilize capacity building for military affairs, economics, and administration for cyber deterrence. Even though the circumstances of cybersecurity are deeply affected by the deterrence theory of Realism, concepts of capacity building for cybersecurity are derived not only from Realism but also from Liberalism and Constructivism. In the end, through this paper, I found that there is an interdependence of Realism, Liberalism, and Constructivism.