Historically, the most important approach in international relation has been realism. It has been the dominant way of explaining international behaviour until recently but it still has many adherents. The realists argue that states are the most important actors in the international system to the virtual exclusion of all other actors (i.e. is the focal point). The security of the state and its citizens is the primary motivation of the state. States also have predatory aims. If a state lies unguarded such that its neighbours can take advantage of it by military or other means, then the unguarded state will find itself attacked. There is, at least latent threat of a war against all. Then, human conditions are one of potential insecurity where predators take advantage of the weak. It is this particular new message which is being sought to be conveyed by the German word “real politik” or “power politics”.
The realist approach or realism in international relations derives its name from the belief of its adherents that they are being realistic and looking at the world as it is. However much we may deplore the approach or criticize it, we have to recognize that this is the way the world is and accept it as such. Indeed if we are going to work for a more peaceful international society we must recognize how people really behave, rather than some idealized version of this. The basic tenets of realism may therefore be summed up as follows:
First, states are the dominant actors in the international scene.
Second, states pursue power; they do this both in the sense of trying to get more powerful positions at the expense of the rivals and by defending themselves against the encroachments of these rivals.
Third, as the relationships of states with each other are dependant entirely on their power relationships with each other, they have nothing to do with the interval structure of the state or the type of regime. Internal politics and external politics are therefore completely separate. This has lead to realism being known as the: billiard ball model of international relations”. The movement of the states like the movement of billiard balls can be explained totally in terms of the movements of the other states.
It follows that for the realist international relations is the analysis of the states pursuing power. The achievement of comparative peace or relative peace is the result of the manipulations of power. All other issues are subordinate to this. However the realists clarify that although this may project a situation of despair. To deplore power politics is like deploring that lions kill their prey in cruel ways. It maybe regrettable but that is the nature of lions. If one comes into contact with them one should take prudent precautions.
Likewise, the realists need not justify or like the world as they see it but they argue that it would be dishonest and self-defeating to pretend that it is otherwise. Some realists known as the neo-realists realized that economic actors were also signified in the international system, but they were reluctant to dethrone states whose power politics they still felt was central to the international system.