The following is the list and corresponding descriptions of the major theories of international relations:
1. Realism: A theory of international relations stating that there is an innate disorder in the international system and the relations among international actors are chaotic due to incessant tussle for power and security.
2. Liberalism: Contradicting the theory of realism is the theory of liberalism. It contends that international relations is not about power politics but interdependence and cooperation among international actors.
3. Constructivism: Another theory of international relations is called constructivism. Unlike realism and liberalism, this theory considers international relations as a social construction and not a product of the actions of international actors.
There are also other contemporary theories of international relations. Take note of the following:
1. Functionalism: Key to the argument of functionalism is that the individual actions of states or nation state governments are obsolete in the international system. To be specific, the international system has responsibilities and concerns that are more important than the responsibilities and concerns of individual states.
2. Marxism: There is a set of theories of international relations inspired by the works of Karl Marx. These Marxist theories focus their analyses on economics rather than politics. They argue that the disorder in the international system comes from class struggles due to capitalism, exploitation of resources, and unequal wealth distribution.
3. English School: An attempt to combine realism and liberalism aimed at understanding international relations through the incorporation of two facets: the individualistic and conflicting aspect of realism, and the cooperative model of liberalism.
4. Green Theory: Another contemporary theory of international relations that revolve around highlighting the role of the environment in influencing the international system and relationship between international actors, as well as arguing how other theories have left out ecological issues in their models and analyses.
5. Feminism: There is another set of theories inspired by the concept of feminism. These theories have collectively contended that masculinity and patriarchy influence the international system, and that struggles for power and security have always been gender-biased.