The main theoretical classification on the role of international relations is structured around: traditional realism, liberalism, Marxism along with constructivism, feminism, the green theory, and other integration theories.

Integration is a process “whereby political actors in several, distinct national settings are persuaded to shift their loyalties, expectations and political activities toward new center, whose institutions possess or demand jurisdiction over pre-existing national states”. The theoretical approaches dealing with integration focus on the development of certain policies as well as institutional and governance structures that exist above and/or beyond the nation-state level.

Functionalism is an integration theory concerning the development, role, and functioning of IOs. David Mitrany, the founding father of the functionalist theory, justifies the establishment of IOs based on their social, economic, political, and other related functions that are deemed essential for promoting the interests of nation states. The functions of IOs provide the basis for the development of common interests and cooperation among nation-states. As is also understood from the information given, the correct answer is A.

Other integration theories are federalism, neofunctionalism, intergovernmentalism / liberal-intergovernmentalism.

Federalism as an integration theory gained prominence in the post-Second World War period. Following the War, the idea of establishing a supranational political union in Europe dominated the agenda of West European nations. The rationale behind this initiative was to prevent any future wars and establish a lasting peace in Europe.

Neofunctionalism, a theory of regional integration, was developed in the 1960s and 1970s as a “moderate conceptual tool” for assessing the European integration process. Neofunctionalism expands the notions of functionalism by combining the “functionalist mechanisms” with “federalist goals,” devoting extensive self-sufficiency to “supranational” institutions.

During the political stalemate in the 1960s, neofunctionalism was highly criticized by the intergovernmentalist approach. In contrast to neofunctionalists’ stress on the role of supranational decision-making bodies in the institutional structure of IOs, prominent scholars of intergovernmentalism such as Stanley Hoffmann point to the decisive role of national/domestic politics for the integration process (Hoffmann, 1966). Intergovernmentalism and liberal intergovernmentalism consider the formation of IOs as a process of inter-state bargaining process wherein socioeconomic interests, the positions of political elite, and ideology matter to a great extent.

The definitions of the other international theories are as follows:

Realism is one of the major theories of international relations. The state-centric approach of realism is accepted as its distinctive trait, since the state is theoretically acknowledged as the main actor in international relations who follows its own interests and compete for power in the international system. Realism considers the concept of power as the ability to change and adjust the behavior of others in an anticipated way. Presuming that the state behavior is mainly shaped by the dynamics of power and security in international relations, it is hypothesized that states can maximize their self-interests by providing their own security and preserving (and even increasing) their own power.

In its debate on international affairs, liberalism focuses on the individual rather than on the state and draws its basic ethical tenets from the value of the human being. Based on the works of Adam Smith such as The Wealth of Nations and of John Locke such as The Essay Concerning Human Understanding, the liberal approach acknowledges the possibility of establishing cooperative relations between not only individuals but also nation states. Accordingly, nation states can build peaceful interstate relations especially through such issue areas as economics and trade. Although liberalism does not assume that war is illusory, at least it defines the nature of international relations as a sequence of cooperation and conflict, not only as a conflictual process as Realists do.

Marxism along with constructivism, feminism, the green theory are critical IR theories.

The Marxist approach contributes to the understanding of international relations and the role of IOs by critically assessing realism and liberalism, which are the dominant theoretical approaches to international relations. Marxism primarily focuses on the role of economic power in international affairs. Marxism criticizes capitalism as the main mode of production on the grounds that it causes inequalities among nation states and thus destabilizes the world order and increases the possibility of a conflict among states. Marxism regards IOs as tools and/or influence mechanisms of capitalism that widen the gap between the developed nations and the developing/ underdeveloped nations.

Constructivism is one of the recent prominent theories of International Relations. The constructivist approach focuses on the epistemology and sociology of knowledge as well as the agentstructure debate. The approach perceives the current world structure through the lens of “social construction of power politics”. Constructivism argues that IOs contribute to bilateral and multilateral cooperation among nation states, despite the fact that their material interests and political power may not be maximized through this cooperation.

As one of the critical theories of international relations, feminism focuses on the role of gender and gender politics in international affairs. Feminism discusses women’s possible role in, and contribution to, the decision-making and policy-making processes within IOs with regard to important issues of international affairs and global governance.

Green Theory: Today’s world is facing a rapid process of globalization that has produced complex and interdependent structures. These complex structures include economic, political, social as well as ecological issue areas where a good global governance has become a necessity. The environmental issues are no longer considered within the scope of nation states. Rather, these issues expanded and many new actors participated in managing them, including “networks of experts, environmentalist organizations and multinational corporations as well as new agencies set up by governments”. This theoretical approach suggests that today IOs play a significant role in the decision-making mechanisms that deal with environmental issues and develop “legally binding” policies negotiated and agreed upon by nation states and non-state entities. In fact, IOs help to strengthen the idea of global governance on environmental issues by reconciling processes of rule-making and rule implementation that takes place at different levels of governance, i.e. sub-national, national, supranational, and international.