Liberal approach to the study of international politics was developed since 17th Century. Liberals traditionally takes a positive view of human nature. Neo-liberals often employ game theory to explain why states do or do not cooperate; since their approach tends to emphasize the possibility of mutual wins, they are interested in institutions which can arrange jointly profitable arrangements and compromises. Neo-liberalism is a response to Neo-realism; while not denying the anarchic nature of the international system, neo-liberals argue that its importance and effect has been exaggerated. Liberals and neo-liberals, however, consider the state and its interests as the central subject of analysis. Liberal Approach of international relation is based on the assumption that individuals are the primary international actors, states interests are dynamic and mutual interest can sustain cooperation in the international system, while neo-liberal approach declines human progress. Unlike the traditional liberals, the neo-liberals are far less optimistic about progress and cooperation. A neo-liberal approach seeks to promote free trade or open markets and western democratic values and institutions. Neo-liberalism believes that all financial and political institutions created in the aftermath of the Second World War have stood the test of time. Neo-liberalism is broadly, divided into four main brands of thinking: institutional liberalism, sociological liberalism, republican liberalism, and interdependence liberalism. Neo-liberals state that states are the key actors in international relations against the realistics who believe that states are only significant actors. In present days, states seek to maximize absolute gain by mutual cooperation. According to the neo-liberals, the biggest obstacles to successful cooperation is non-compliance by states. And such fears are emanate from the sovereign states. Neo-liberals recognise that the cooperation may be harder to achieve in areas where leaders perceive they have no mutual interest. But the states are willing to shift loyalty and resources to institutions if they are mutually beneficial and increase opportunities to secure their international interests.