Overview of realism and liberalism Liberalism and realism are among the theories that are commonly used in political science in explaining the relations between players in the international political scene. The assumptions of the two theories contradict each other. While realism is taken to portray pessimism in the relations between states in the international system, liberalism depicts optimism and positivism in as far as the relations and goals of states in the international system are concerned. Realism depicts competition in the relations between states. According to the proponents of realism, every action in the relation between states is guided by the urge to pursue and promote the interests of a given nation state. Nation states act to safeguard their interest, which implies that the action of any state is geared towards safeguarding the interest of that state. They care less about the interests of other nation states. On the other hand, liberalism depicts a change in the international scene that aims to enhance interaction between nation states in various aspects of development. Liberalism depicts optimism in the domestic and international affairs. Liberalism as a philosophy in political economics focuses on the change in policies and legislation in order to promote the development of nation states. Liberalism concerns the search for a means of embracing freedom and openness in the participation of nations in political, social and economic affairs. Liberalism, realism and the concept of power There exist a substantial number of theories that seek to explore the concept of power in domestic and international relations. Power is one of the key concepts that dictate the relation between states on the international system. Liberalism and realism are two key theories that depict two pictures that coexist, yet they are different in theory. Realism and liberalism differ in the manner in which they depict power in the relation between actors on the domestic and international scene. One critical thing about realism and liberalism is that they confide and believe in the need for power by actors Lukes (2005). However, there is a difference in the manner in which the two theories expresses the channels of pursuing power by the actors. Realism and the comprehension of power According to Wechsler (2010), realism is a theory that is two dimensional. The theory was advanced in the mid of the 20 th century by Hans Morgenthau. The development period of this theory is critical to understanding the dimension of the theory in explaining the concept of power. The theory was developed at a time when the world was witnessing a vacuum in the balance of power, which was created by the Second World War. Realism can be comprehended from the 19 th century European politics where power was one of the main issues that brought about conflict between European nations. The 19 th century Europe was characterized by numerous wars and territorial conquests. These developments entered the 20 th century and developed through the mid of the 20 th century. The balance of power was the key center of friction between the United States and the Soviet Union during the cold war. The current political developments in international relations, therefore, cannot be separated from the concept of