Realists/Liberals believe that: Unlike liberals, realists believe that war is inevitable based on their view of human nature. Realist thinkers like Morgenthau believe that humans are self-centred and pursue their interests above and beyond any concern for harmony and balance and that causes an instability and tension which will make war inevitable whereas liberals believe that humans are guided more by reason which can provide harmony and balance. Unlike liberals, realists believe that war is inevitable based on their view of an anarchical system. The idea of an anarchical system is that there is no hierarchical, superior power that can provide the stability required for harmony and balance and that this leaves states in a self-help system where war is inevitable. The realist perspective on the Security Dilemma explains why, unlike liberals, they see an inevitability of war and conflict. The Security Dilemma occurs when one state takes action to increase its security leading to other states following suit which in turn leads to unstable arms races and then to war and conflict which makes harmony and balance impossible. Unlike realists, liberals see a growth in complex interdependence as reducing the likelihood of war and conflict and providing for harmony and balance. Complex interdependence describes how states are increasingly linked through international organisations, trade and the need to resolve global issues which can’t be resolved at a state level, thus complex interdependence makes war and conflict far less likely between states, linked to the Kantian Triangle as states find common ground. The realist concept of the billiard ball model helps to explain why states are unlikely to achieve peace and harmony. Realists believe in the billiard ball model in which states collide based on different interests and that the anarchy connected with the billiard ball model will make war inevitable unlike liberals who believe in a more harmonious cobweb model where harmony and balance can develop. Conservatism core ideas and principles and how they relate to human nature, the state, society and the economy. Hobbes-and the consequences of this for the state system and for likelihood of cooperation, his negative view of human nature and the dangers to civil society and likelihood of conflict. Socialism core ideas and how they relate to human nature, the state, society and the economy. Greater optimism on human nature linked to the natural relationship among humans being cooperation and work for the common good – Marx - which makes the idea of a global society order and cooperation likely. Liberalism core ideas and how they relate to human nature, the state, society and the economy. Emphasis on the benefits of mutual cooperation and order and avoidance of war from both an economic and practical position – Locke.