The term International Relations refer to the study of the relations of states with each other and with international organizations and certain sub-national entities (e.g., bureaucracies, political parties, and interest groups). It is related to a number of other academic disciplines, including political science, geography, history, economics, law, sociology, psychology, and philosophy.

Though international relations as an academic discipline is of recent origin, yet relations among nations were as old as phenomena of history. It acquires its own identity after the First World War.

The term international relations as such refer to the totality of interactions within the international system. It is an ongoing process owing to the continuous changing world scenario. World community is so dynamic and international environment changes so rapidly that one studied few years ago with keen interest becomes obsolete or outdated today.

This makes it a ticklish job to define the exact meaning of international relations.

However, international relations is a specialised academic field. It essentially deals with the interactions between and among states, and more, broadly, the working of the international system as a whole.

Therefore international relations can be conceived of either as a multidisciplinary field, gathering together the international aspects of politics, economics, history, sociology, law etc., and focussing on the systematic structure and patterns of interaction of the human species taken as a whole.

The nature of international relations simply means the characteristics of international relations. This ‘nature’ is not static but dynamic. The nature of international relations keeps on changing with the passage of time.

International relations focus mainly on three things, such as:
i) National interest
ii) Conflict
ii) Power

Every nation wants to pursue their national interests for their own development in various fields. While pursuing the same, sometimes conflict arises from the incompatibility of interests of nations. Nations try to safeguard their interests by influencing and controlling the behaviour of other nations. For instance, when China extended its territory over the Indian territories, war between the two broke out in 1962.

But at the same time, interests of some nations may be identical as well. International relations thus involve both conflict and cooperation. Therefore, international relations are a phenomenon of recurring pattern of conflict and harmony.

There are various developments that brought about change in the nature of post-1945 international relations. Some of them are as follows:

i) Multiplication of sovereign states:
After the Second World War, new sovereign states appear on the international scene. With this, international relations can no longer be considered as an activity between only great powers especially of the European countries. As a result, international relation has really assumed international character.

ii) Public opinion:
Public opinion plays an important role in changing the nature of the international relations. In today’s world, unlike earlier days, due respect is given, as far as possible, to the wishes of the people. Accordingly, foreign policy makers have to satisfy not only on national but also worldwide audience. American public opinion on ‘Vietnam’ in 1968 is an epitome.

iii) Ongoing technological development:
After the development of Atom bomb and other deadly weapons, the concept of victory has become meaningless, for nuclear war involves the danger of mutual suicide. This defencelessness against nuclear weapons has brought radical change in the nature of international relations and consequently in the nature of power.

To conclude, it may be argued that the meaning and nature of international relations is continuously changing along with changes occurring in different parts of the world. The same pattern would continue even in the years to come.