The Origins of War

The invention and spread of agriculture coupled with the domestication of animals in the fifth millennium B.C. are acknowledged as the developments that set the stage for the emergence of the first large-scale, complex urban societies. These societies, which appeared almost simultaneously around 4000 B.C. in both Egypt and Mesopotamia, used stone tools, but within 500 years stone tools and weapons gave way to bronze. With bronze manufacture came a revolution in warfare.
This period saw the development of many new weapons -- the penetrating axe, armor, helmet, composite bow the wheel and chariot -- and gave birth to a number of tactical innovations -- phalanx formations, increased mobility, pursuit, emergent staffs and rank structures. It would be incorrect to conclude, however, that new weapons were responsible for the great increase in the scale of warfare that characterized this period of human history. Improved weaponry, by itself, would have produced only a limited increase in the scale of warfare unless accompanied by new types of social structures capable of sustaining large armies and providing them with the impetus and means to fight on a heretofore unknown scale. The military revolution of the Bronze Age was rooted more in the development of truly complex societies than in weapons and technology.
What made the birth of warfare possible was the emergence of societies with fully articulated social structures that provided stability and legitimacy to new social roles and behaviors. The scale of these fourth millennium urban societies was, in turn, a result of an efficient agricultural ability to produce adequate resources and large populations. It is no accident that the two earliest examples of these societies, Egypt and Sumer, were states where large-scale agricultural production was first achieved. The revolution in social structures that rested upon the new economic base was the most important factor responsible for the emergence of warfare.
These early societies produced the first examples of state-governing institutions, initially as centralized chiefdoms and later as monarchies. The new government structures gave a degree of stability and permanence to the centralized direction of social resources on a large scale. Chiefdoms supported by organized but still small-scale armed forces forged the scattered elements of the protosocieties into true social orders. At the same time, centralization demanded the creation of an administrative structure capable of directing social activity and resources toward communal goals. By 3100 B.C., such an administrative structure, complete with writing and formal record keeping, was already evident in Egypt, and by 2700 B.C., it was present throughout the states of Mesopotamia. Although these structures were probably first employed on large scale public works projects -- building dikes, irrigation systems, the pyramids, and ziggurats of ancient Sumer -- it was but a short step to employ these new organizational resources in the service of warfare.
The development of central state institutions and a supporting administrative apparatus inevitably gave form and stability to military structures. The result was the expansion and stabilization of the formerly loose and unstable warrior castes that first emerged in the tribal societies of the fifth millennium. By 2700 B.C. in Sumer there was a fully articulated military structure and standing army organized along modern lines. The standing army emerged as a permanent part of the social structure and was endowed with strong claims to social legitimacy. And it has been with us ever since.
As important as these developments were, they could not have worked as they did without a profound change in the psychological basis of the people's social relationship with the larger community. The aggregation of large numbers of people into complex societies required that those living within them refocus their allegiances away from the extended family, clan, and tribe, and toward a larger social entity, the state. This psychological change was facilitated by the rise of religious castes that gave meaning to the individual's life beyond a parochial context. Organized belief systems were integrated into the social order and given institutional expression through public rituals that linked religious worship to political and military objectives that were national in scope and definition. Thus, the Egyptian pharaoh became divine, and military achievements of great leaders were perceived as divinely ordained or inspired. In this manner the terribly propulsive power of religion was placed at the service of the state and its armies.
It is important to remember that the period from 4000 to 2000 B.C. was a truly seminal period in the development of the institution and instrumentalities of war. When this period began, people had not yet invented cities or any of the other social structures required to support communal life on a large scale. Agriculture, which became the basis for the nation-state in the ancient period, was still in its infancy and could not yet provide a food supply adequate to sustain populations of even moderate size. Psychologically, people had not yet learned to attach meaning to any social group larger than the extended family, clan, or tribe. The important force of religion had not yet been given specific social focus to the point where it could become a powerful psychological engine to drive the spirit of conquest and empire. Even warfare itself had not in any meaningful sense been invented. There were only the embryonic beginnings of a warrior class still loosely embedded in a tribal social structure, a structure that lacked both the physical and psychological requirements to produce war on any scale. Military technology and organization were primitive, and the professionalization of armies and warfare had not yet begun. In any significant sense warfare had not yet been embedded in the social structure of man as a legitimate and permanent function of developed society. The two thousand years following the dawn of the fourth millennium changed all this. As a mechanism of cultural development, the conduct of war became a legitimate social function supported by an extensive institutional infrastructure, and it became an indispensable characteristic of the social order if people were to survive the predatory behavior of others. This period saw the emergence of the whole range of social, political, economic, psychological, and military technologies that made the conduct of war a relatively normal part of social existence. In less than two thousand years, man went from a condition in which warfare was relatively rare and mostly ritualistic in which combat death and destruction were suffered at low rates to one in which death and destruction were attained on a modern scale. In this period, warfare assumed modern proportions in terms of size of the armies involved, the administrative mechanisms needed to sustain them, the development of weapons, the frequency of occurrence, and the scope of destruction