A war is a conflict between state-like entities. It is usually a violent confrontation that may include the use of regular or irregular military forces. It can take many forms, from negotiated ceasefires to a ruthless campaign of destruction. The aims of states in war may be political, economic or territorial in nature. It can also be a form of conflict between non-state actors, as in the case of insurgencies or terrorism. In terms of the human costs, it can be extremely destructive to individuals and communities. Deaths as a result of war are well documented but other consequences of it, such as long term disability, poverty, malnutrition, social/economic disintegration and mental illness, have not been as widely recognised.

The nature of war has changed considerably over time. In recent years the ability of non-state actors to acquire weapons and engage in violence has dramatically increased. As the globalisation of the world has expanded, so too has the international scale of conflicts.

This trend has created new possibilities of conflict and in turn stimulated the development of innovative military technologies. The proliferation of weapons has made warfare more unpredictable and difficult to control. Moreover, the increasing globalisation has meant that the boundaries between state and non-state actors have become less defined.

These developments are transforming the way that the world views war. On one hand, some argue that war is not only a ‘natural’ phenomenon that the strong nation has a right to impose upon the weak. Others, such as fascists, assert that there is a need to use force in order to fulfil the will of the people.

Yet other states view war as a strategic tool that is used to achieve political ends by means that may not be considered moral or ethical. These views are based on the idea that war can be controlled, influenced and even prevented through sound planning and the exercise of the strategic imagination.

A third perspective argues that the use of military force is an essential feature of modern politics. It considers war as a ‘clash between major interests, which can only be resolved by bloodshed’. This argument is based on the fact that there are some states that are not willing to compromise with others and that they may be reluctant to make peace.

Whether this perspective is correct is not clear but it does highlight the importance of considering how the concept of war is understood. The word itself is often used in a colloquial sense, as children do when they play games, and it is not necessarily understood as referring to a state-sponsored attack. This makes it particularly important to develop a working definition of war that includes the range of possible perspectives. This will allow us to better understand the changing nature of this phenomenon. It will also enable us to distinguish between the traditional, rationalist view of war and more alternative models such as guerrilla wars.