War can be seen as both a scourge of mankind and a central institution of global politics. Despite the terrible suffering and loss of life which wars cause they also can be seen as performing important functions for the ordering and maintenance of international society. War has been used to maintain the balance of power. That is, to prevent one state or a group of states from disrupting the status quo, through the use of violence. .
Without effective means of a peaceful settlement of disputes, war has provided a mechanism through which states can implement a rule of law in their favour or redress unjust practices. In the absence of an international police force, states have reserved a monopoly on the use of force in order to preserve and maintain their interests. This double perspective (the horrors of war and its social role in global politics) haunts us today in a world where the possibility of nuclear war threatens to spell the end of civilisation. The United States and its allies may possible attack Iraq any minute from now, The prospect of peace in the Middle East is in its lowest ebb ever, India and Pakistan are threatening each other. We live then with the ever-present reality of war and the fear of total annihilation. .
Developments in industrialisation, military technology and mass society have changed the face of modern warfare. The twentieth century has witnessed wars of appalling destructiveness, global warfare and innumerable local wars. The advent of total war, that is, war against entire populations for unlimited stakes made war at best a dangerous instrument of state policy. The development of nuclear weapons has made war (especially conducted between nuclear states) an irrational device for the peaceful solution of disputes. .
As a student of International Relations I don't want to conclude however that because war is dysfunctional it will not occur. To do so would be to assume that war is always a rational act or always arises from rational decision-making.