Realism in international relations refers to the classical belief that states vie for power using economic and military means. Human nature is, according to the realist, self-serving and unavoidably power-hungry. Thus, the theory is concerned mainly with how states vie for economic and military dominance in the world's political arena and how to navigate through a usually treacherous world. Subsequently, realist international relations are based on power politics. Realism infers that states act selfishly, unilaterally, and largely independently. International rule of law and political norms are virtually nonexistent in the realist perspective. Liberalism, on the other hand, offers a more nuanced perspective on international relations. Classical liberalism presumes that states do not act solely out of want for economic and military dominance. States are comprised of peoples and cultures, and their corresponding value systems. Moreover, a liberal theory of international relations points to the emergence of globalization...

Pluralism, multilateralism, and heterogeneity are integral to liberal theories of international relations.
Clashes between realism and liberalism have expanded international relations discourse and have given rise to neo-realism and neo-liberalism. An extension of liberal international relations theory, neo-liberalism posits the creation of global institutions and rules of law that promote common welfare and mutual benefit. Unlike either liberalism or neo-liberalism, neo-realism presumes an underlying anarchy in international law. In the absence of global norms, the neo-realist urges sovereign states to continue acting out of self-interest in the pursuit of military and economic prowess while allowing for some rule of law. In general, realism and neo-realism offer more pessimistic and conservative views of international relations than either liberalism or neo-liberalism.

2. Neo-realism and neo-liberalism offer widely…