-According to Realism, Liberalism, Constructivism, and Marxism approach-
The war has profound and fundamental causes in each age and for all the societies.
According to Realist theorists, the concept of power has a center emphasis in the human life. Therefore, the human is ambitious and greedy since it’s birth because of the obtaining power. In this context, national power is a momentous concept for states. States also want to increase and maximize its power as the human.
Based on realist theory; states are acting with increasing motivation continuous capacity. Possibly, they try to get others to dominate. Thus, if a war necessary for the protection of national interests, the war should be occurred. According to realism; cause of the war, the conflicting interests of the state want to protect their own national interests. Therefore, in this context, the war and conflict are becoming commonplace.
On the other hand, according to Liberalist theorists, although human nature tends to interests conflict, through cooperation and reconciliation can protect the interests of all actors. Therefore, it is not always in the forefront of military power, ideals and economic interests are also important.
According to the Liberals, the causes of war, must look at the states have a self-sufficient ‘economic nationalism’ application. The pursuit of self-rule government protectionist policies, which ultimately led to colonialism. As a result of this, colonialism deepen economic competitiveness and increases the possibility of war.
According to Alexander Wendt, over time the interstate alliances increases; in international relations, cultural values are the main factors in common, such as power and interests cases.
Wendt’s Social Constructionist model is based in the state. Because this theory sovereign state in the medium term are considered to be the main actors in the international system. In fact, the new entity will be realized through the state channels. Identities, ranged, depending on the interstate dialogue, governments come together by sharing a common identity and common principles.
War is based on the assets that comprise identification. From this point, Identity shaping and restructuring process leads to war. Therefore, that of a restructuring phase and that it happened in the formative stages of reshaping of identities language, exhibits a dominant performance factors such as religion and culture.
Lastly, Marxists insist the main emphasis on economic aspects. For example; Marxists see the war as a result of the international dynamics of the capitalist system. Capitalist states want to keep their profit level by providing the same level of control on new markets, raw materials or cheap labor resources. Therefore, they must continually grow and expand.
In this case, conflict is inevitable. Therefore all wars are wars looting carried out for the interests of the capitalist class.
As a result, Realists, Liberals, Constructivists and Marxists have put forward different views about the causes of war, and reason behind the international conflict and war. We see that every response of the theories on the real politic.