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.

In recent years, cyber-attacks in virtual spaces have been rapidly increasing, and modern centralized states have proven to be incapable of effectively responding to cyber-attacks on their own. To resolve cyber issues, the United States has started cooperating with allied countries such as Japan and the ASEAN countries through Capacity Building (CB). Cyber-attacks include online and physical infrastructures, often referred to as electronic warfare and “hybrid wars.” In this paper, I show the importance of revisiting deterrence theory for cyber security issues. Deterrence theory derives from a traditional International Relations (IR) theory, realism, which emphasizes that states always act to maximize military power. However, in explaining the CB in cyberspace, key concepts and different theoretical frameworks which both scholars of liberalism and neoliberalism advocate, must be incorporated because not only military power, but also economic power has to be taken into account. This paper takes the United States as one case in which infrastructural support in cyberspace is observed. More specifically, I argue that in order for CB to happen, cooperation in cyberspaces must emerge, especially in the realm of economy, legislation, and military support to allied countries. This paper intends to determine the utilities of cyber CB. To do so, I collected data from more than 200 countries and inspected the correlations between cyber-attacks and CB using statistical software R. I also examines other factors such as Internet population, GDP growth rate, war expenditures, economy, military, and law regimes, to determine which are statistically significant in mitigating cyber-attacks.   Keywords: cybersecurity, international relations, realism, liberalism, capacity building