According to Levy, the individual level cause of conflict/war is mainly due to human nature and depends on an individual’s aggressiveness, personality or psychological process. The state or national level cause of war depends on the political system of a country, cultural factors such as ethnicity and nationalism, and economic factors. The international system can also be referred to as the systemic level of conflict causes. The systemic level contains factors such as global system and power structures. The individual level of conflict theory presumes that individuals can be the cause of conflicts in or among states. Individual leaders can lead to wars due to their emotional states such as trauma or aggression. It has been scientifically proven that an individual’s emotional state for example trauma or aggression can lead to poor judgment and decision-making process. For example, a leader can be naturally aggressive and due to this person is highly irritable and anything he considers as offending from an ally or foreign state may lead to him readying up his troops and sending them to war as a result. Trauma refers to shock and this can also lead to an individual who is a leader to pass poor judgment and decisions in the face of a conflict which leads to wars.
The power theory stipulates that a few countries may have vested interests in trying to achieve their own vested goals and therefore they act to advance their interests to increase their power, security or wealth. Such countries advance their interests by overstepping the boundaries of other sovereign states and this leads to wars and conflict. Superpower countries also tend to build up arms and form alliances with cooperating countries to protect their interests and this can at times anger a few opposing sovereign states and thus leading to wars. The global structural setup may also lead to wars and conflicts among states. The lack of a clear and legitimate authority which can regulate and enforce agreements among disputing states may lead to the rise of conflicts. The existence of an authority to which all states are answerable can help in minimizing wars and conflicts. The cultural setup among different countries can also lead to conflict. For example, countries that break away from other countries as groupings of ethnonational groups are likely to be in conflict. Such countries tend to go into a state of anarchy due to the lack of clear leaders and or national figures who offer direction after the split and therefore the existing uncertainty results in war and conflict between such ethnonational countries (Crocker, Hampson &Aall, 2008). The state-level theory focuses on factors which are the cause of conflicts in a state or country. Factors such as nationalism, ethnicity, political and economic structures may be the contributors of conflicts in a certain country. The probability of occurrence of a war in a country is likely to be influenced by the fairness of its political systems.