Hobbes describes realism as all men interacting in anarchy and are equal. They are motivated by competition (scarcity), glory and diffidence. Realism emphasizes on constrains on politics imposed by egoism and the absence of anarchy which require ‘the primacy in all political life of power and security’ (Donnelly, 2009).Realists rely on themselves and do not recognize any authority in anyone and pursue power at all cost at national interest to achieve sovereignty which results them to maximize their military power to ensure survival. This leads to security dilemma (Dunne & Schimdt, 2011).

The main difference between classical realism and neo-realism is the determinants of state behaviour. For neo-realists, the balance of power is a main motivation due to human nature According to the 6 principles of Morgenthau’s Politics of Nation, politics is governed by laws created by human nature and revolves around the concept of interest, defined in terms of power. This leads to classical realists being pessimistic. States act in a selfish and competitive manner in a constant state of anarchy seeking power. Neo-realists however think that economic resources and military powers are important to influence other states to achieve hegemonic stability (Dunne & Schimdt, 2011).
Realism revolves around 3 core elements; statism, survival and self-help.
Statism is the ideology that instils the belief that community are protected and sustained by states. This allows the states to increase their power to establish security. The increase in power of one country leads to hegemony.
Realists believe that maximum power will lead to survival. This leads to double moral standards when it comes to dealing with domestic and international affairs as states follow different ethics. Mearshimers (offensive realism) states that self-help is the basic principle of action. There is no satisfied or status quo states. The accumulation of more power than anyone else is the best way to peace. According to Waltz (defensive realism) the lack of anarchy forces states to behave in a self-help manner in order to survive. Due to the anarchic system, there is a differentiation of units which leads to survival of each state depending on its own resources as they can’t rely on others to provide. This leads to states being separated by their capabilities. Realists do not believe that a state should depend on international agencies for survival as there is no hegemony. The survival of realists exists when the balance of power exists (Dunne & Schimdt, 2011).

A liberalist holds an optimistic view of human natures and the norms of constitutionalism and democracy. Kant, author of ‘Perpetual Peace’ thinks that war is irrational and it’s better to optimise welfare (Beeson, 2012).Liberalism pulls in 2 directions as a commitment to individual freedom in economic and social spheres and a democratic political culture for basic freedom where one builds good rapport with different countries and warfare is unnecessary to settle disputes (Dunne, 2011). Neo-liberals however think that states should cooperate to achieve absolute gains (Lanny, 2011). The influence of neo-liberalism lead to the proliferation of free trade agreements and organisation like NAFTA, WTO,G8, APEC, and IMF. (Burchill, 2009)

Economic liberalism arose when Adam Smith and David Ricardo argued that free trade through the ‘invisible hand’, encourages competition and comparative advantage that would lead to better and cheaper products and thereby prosperity (Kelton, 2010). Liberals believes that undemocratic state leaders and out dated policies like the balance of power should be swept away to prevent conflict by creating a harmony of interest through international organizations like UN and international laws (Dunne, 2011) Neo-realists think that institutions are the means to achieve cooperation to secure national interests for example the cooperation and multilateralism when President Obama worked with the G20 to curb the global economic crisis (Lamy, 2011)