The most keenly debated issue in international relations has been the pessimistic view of realism and the optimistic view of liberalism. Realism is regarded as the dominant theory of international relations, while liberalism has a strong claim to being the historic alternative. Comparing the two to the main political parties in a democracy, Timothy Dunne wrote, ‘Rather like political parties, realism is the natural party of the government, and the liberalism is the leader of the opposition.’

The liberal tradition in international relations in its is closely connected with the emergence of the modern liberal state. The focus of liberalism has been on freedom, cooperation, peace and progress. It has often been identified with individualism, as it insists on freedom of the individual, his rights and property. It is also closely associated, mainly by its critics, with capitalism. Liberalism is sometimes associated with the views of Mo Ti, who was a contemporary of realist Chinese scholar Sun Tzu. Both gave their opposing views more than 2,000 years ago.

Basic Assumptions Of Liberalism
Liberalism assumes instead portraying lust of power as the international conflict liberalism fights for the basic rights of the people. It insists on pursuing the political reforms establish democracies. It emphasizes on the value of the free trade on the basis that it will help in preventing the conflicts between nations as it reduces the national selfishness and enhances the communication.

Liberalism advocated the formation of the global institutions such as the United Nations which sees any threat to any individual nation as a threat to everyone. The institutions help in resolving the conflicts by mediating the conflicts in the event of any misunderstanding.

Basically liberals assume that states will act in a rational manner and they are a unitary actor.

The liberalists fell into three different groups as classified by the realists: The first group advocated league of the nations was formed with the objective to consider the attack on the nation as an attack on all. The second group formed the Permanent Court of International Justice that would lead to formation of judicial body capable of issuing justices to the disputes. The third group sort to avoid war by advocating “Disarmament“ in order to reduce the international tension.

Neoliberalism is a policy model that encompasses both politics and economics and seeks to transfer the control of economic factors from the public sector to the private sector. Many neoliberalism policies enhance the workings of free market capitalism and attempt to place limits on government spending, government regulation, and public ownership.

Neoliberalism is often associated with the leadership of Margaret Thatcher–the prime minister of the U.K. from 1979 to 1990 and leader of the Conservative Party from 1975 to 1990–and Ronald Reagan, the 40th president of the U.S. (from 1981 to 1989). More recently, neoliberalism has been associated with policies of austerity and attempts to cut government spending on social programs.

Liberalism VS Neoliberalism
At its core, liberalism is a broad political philosophy; it holds liberty to a high standard and defines all social, economic, and political aspects of society, including–but not limited to–the role of government. The policies of neoliberalism, on the other hand, are more narrowly focused. They are primarily concerned with markets and the policies and measures that influence the economy.