In this era of rapid technological change, the nature and causes of war are continually being challenged and re-imagined. But the underlying factors of war have not been altered fundamentally: it still involves violence and enmity, chance and friction, rationalised political objectives, dynamic interaction and unpredictability. It is still a messy business, best described by the famous maxim of Prussian general Carl von Clausewitz: “War is simply politics by other means.”

Its ruinous costs mean that most nations have strong incentives to avoid open fighting. They therefore work hard to defuse tensions and to resolve disputes peacefully, even when their rivals appear intransigent. But it is difficult for any power to completely defuse tensions and conflict because it has to retain the ability to defend itself from aggression by its rivals, large or small. This is one of the core insights from both history and game theory: war is a last resort.

War is also a complex phenomenon, and the causes of it are complex. The basic causes of war include a state’s desire to impose its will on the international arena, its ability and willingness to project its power, and the natural balance of power in the world.

Moreover, there are many inter-related causes of war that operate in combination and in time. These are generally referred to as “conflict behavior.” These include coercive and noncoercive paths, with the former involving military force and the latter embracing cooperation and cooperative behavior. A common approach to visualising these is a phase map.

The elucidation of the phases of a phase map can help in understanding the complexity of the underlying forces that lead to war. For example, some experts argue that a nation’s ability to utilise its resources is a key factor in its capacity to fight a war. These resources may be financial, natural or human capital. In addition to this, there are a range of other factors such as domestic pressures, bellicose culture and reaction to perceived injustice.

A number of authors have proposed that cultural determinism is the primary cause of war, although there are differences in opinion about whether these factors can be reversed or eliminated. Others are concerned about the nature and extent of man’s inherent inclination towards aggression, and about whether there can be any form of pacifism that will overcome this.

Despite the recent and ongoing advances in weapons technology, it is unlikely that any significant new weapons or tactics will be developed that will eliminate the need for nations to engage in war. This is largely because existing international law and tribunals, such as the ICC and the ICJ, have proved only marginally successful in limiting the scale of warfare, and their jurisdiction is limited by the fact that they are unable to prevent conflicts and wars before they begin. As a result, it is probably more important to reduce the incentives for wars and to develop broader methods of conflict resolution than to find a way of preventing or resolving them.