[pp. 68-71] Another aspect of warfare involves to what degree conflict is linked with other interaction among the opponents. Many societies trade or even exchange mates with another group during part of the year and launch raids on them in another. Planning a massacre treacherously disguised as a feast or celebration is an example of such shifting behaviors and is a recurrent theme around the world. An ethnographic account related to anthropologist Napoleon Chagnon in the 1960s by Kaobawa, a leader of a small Yanomama village, reveals how this could happen. Kaobawa’s group, with few allies and under pressure from its enemies, tried to form an alliance with a neighboring group. This village was actually part of the enemy alliance and set about to take advantage of Kaobawa’s desperation by inviting his group to a purported feast. When they arrived at the host village, “the men of Kaobawa’s group danced both singly and en masse and were invited into the homes of their hosts. At this point their hosts fell upon them with axes and staves, killing about a dozen before the visitors could break through the palisade and escape.”
The Germans and Russians were actively trading materials useful in warfare until the day before the Nazis attacked in World War II. In the New Guinea highlands, raids often had to be planned in secret, excluding the men and women with close relatives among the group to be attacked, because they were expected to warn the intended victims. All types of societies from foragers to states have these friend-enemy dual relationships.
The evidence for and characteristics of past warfare come together, again, in Tikopia, that particularly appropriate example from the “paradise” of the South Pacific. In spite of the efforts to control population, including infanticide and periodic “explorations” for resettlement, the Tikopians could not control their numbers, nor were the sea and land of limitless bounty. In such a small society, with an entire island population of fewer than fifteen hundred people, severe resource stress would not be expected to result in warfare. If there were any place where people might starve when all other courses of action were exhausted, it would be a small island in the middle of nowhere. Yet there was warfare in paradise. At one time Tikopia had three political entities. In the mid-1700s, the group living in the least productive area of the island virtually annihilated the other two political entities or forced them to flee. We know from historical accounts that at least one other major act of warfare had taken place a couple of centuries previously. When Tikopia was not under a single political leadership, violent and annihilating warfare took place at least every few centuries.
Having discovered that evidence for past warfare can be found just about anywhere in the world where reasonably good archaeological research has been undertaken—and historical and ethnographic accounts show the same thing—it was clear that the idea of a peaceful past was just a myth. With this in mind, I turned back to my two decades of research in the Southwest and wondered why all this warfare was occurring. The one common thread I found with all warfare, inducting that from the Southwest, was that it correlated with people exceeding their area’s carrying capacity. Ecological imbalance, I believe, is the fundamental cause of warfare. It is one thing to believe this but another to demonstrate this relationship. To do so, one must be able to show that there was such an ecological imbalance. In addition, one needs to be able to provide an idea of how resource stress would lead to chronic and continuous warfare and not some other outcome.
Getting archaeological evidence of carrying-capacity stress requires being lucky and clever, so it is spotty. Evidence for climate change, which affects carrying capacity, is easier to find. In a place like the Southwest, where farming is, and probably always has been, marginal, climate deterioration should coincide with food shortages. The archaeology of the region as a whole shows that when the climate was good, the population grew and there was not much warfare. When the climate deteriorated, warfare intensified, as seen in El Morro where I encountered warfare and the rapid building of fortified towns. Warfare did seem to change with good times and bad times. Although my team had trouble assessing the level of carrying-capacity stress at the time the people lived on the hilltops in the Mimbres Valley, when we placed these sites in a regional context, it made sense. Warfare in the region was real and patterned. If the ancient people of the Southwest responded to changes in the climate with less or more warfare, then warfare was a result of some external event and not caused by anything intrinsic.
It is possible to describe a model of how human reproductive potential combined with limits to the carrying capacity results in ecological
imbalance and warfare. If humans did not have mechanisms to keep from over-exploiting their resources over the long run and could not keep their populations far enough below the carrying capacity to avoid being regularly subjected to food stress, starvation must have been a constant threat in the past. Once the notion of the inherent conservationist is recognized as a myth, it becomes obvious that humans would have encountered food stress on a regular basis. In fact, regardless of the type of human organization, this stress occurred in the past, as archaeology and history show.
Before starving, humans perceive themselves to be falling below what they consider their minimal standard of living. As I learned in Samoa, it may take several months for a food crisis to develop after a natural disaster, and such an impending crisis can be anticipated. People recognize what is happening long before it seriously affects them, and they react if they can. For most animals, natural disasters, disease, and starvation are the population limiters. Though human numbers are subject to disease and natural disasters (and there was little we would have been able to do about them in the past), starvation is a very different matter. Starvation is different because humans, with their brains and social structures, can do something about the fact that they are running out of food. Humans starve only when there are no other choices. One of those choices is to attempt to take either food, or food-producing land, from someone else. People do perceive resource stress before they are starving. If no state or central authority is there to stop them, they will fight before the situation gets hopeless. Resource stress in the form of hunger, and not starvation, is what precipitates warfare. If resource stress is the normal human condition, then warfare must have been an integral part of life most of the time in most places.
As human numbers go up, starvation and disease can possibly keep the population in check. This is one potential scenario, but it never seems to have happened in the past. It is hard to imagine an entire society that would let starvation control its numbers. Even the most passive of pacifists will admit that people will fight before they starve—especially if the threat of starvation is a chronic, recurring event. Even natural disasters that may result in food shortages can cause a reaction. Most catastrophes are more likely to have instigated warfare than to have caused groups to wait to see who would starve first. Rarely does starvation, or even its threat, run rampant without conflict developing.
This does not mean that warfare is inevitable. Humans could choose to starve, or the leaders could choose to let part of the population starve. The starving peasants in more complex societies, whether in China, Ireland, Japan, or the Yucatan, would probably have fought for food before starving, but they were usually not allowed to by the central government. On some occasions, there may have been no one in the vicinity from whom to take resources. An Eskimo band that ran out of food did not have the option of taking it from someone else if they had no nearby neighbors. Most people had other societies near enough that fighting and taking was always a possibility. When resources were critically short, fighting for them has been an option for humans for more than a million years.