However, the mass of archaeological evidence and oral accounts of war before European contact discussed above makes it far-fetched to maintain that people were traditionally peaceful until those evil Europeans arrived and messed things up. There can be no doubt that European contacts or other forms of state government in the long run almost always end or reduce warfare, because all state governments don’t want wars disrupting the administration of their territory. Studies of ethnographically observed cases make clear that, in the short run, the initiation of European contact may either increase or decrease fighting, for reasons that include European-introduced weaponry, diseases, trade opportunities, and increases or decreases in the food supply.
A well-understood example of a short-term increase in fighting as a result of European contact is provided by New Zealand’s original Polynesian inhabitants, the Maori, who had settled in New Zealand by around AD 1200. Archaeological excavations of Maori forts attest to widespread Maori warfare long before European arrival. Accounts of the first European explorers from 1642 onwards, and of the first European settlers from the 1790s onwards, describe the Maori killing Europeans as well as each other. From about 1818 to 1835 two products introduced by Europeans triggered a transient surge in the deadliness of Maori warfare, in an episode known in New Zealand history as the Musket Wars. One factor was of course the introduction of muskets, with which Maori could kill each other far more efficiently than they had previously been able to do when armed just with clubs. The other factor may initially surprise you: potatoes, which we don’t normally imagine as a major promoter of war. But it turns out that the duration and size of Maori expeditions to attack other Maori groups had been limited by the amount of food that could be brought along to feed the warriors. The original Maori staple food was sweet potatoes. Potatoes introduced by Europeans (although originating in South America) are more productive in New Zealand than are sweet potatoes, yield bigger food surpluses, and permitted sending out bigger raiding expeditions for longer times than had been possible for traditional Maori depending upon sweet potatoes. After potatoes’ arrival, Maori canoe-borne expeditions to enslave or kill other Maori broke all previous Maori distance records by covering distances of as much as a thousand miles. At first only the few tribes living in areas with resident European traders could acquire muskets, which they used to destroy tribes without muskets. As muskets spread, the Musket Wars rose to a peak until all surviving tribes had muskets, whereupon there were no more musket-less tribes to offer defenseless targets, and the Musket Wars faded away.
In Fiji as well, the introduction of European muskets around 1808 made it possible for Fijians to kill each other in much larger numbers than they had traditionally been able to do with clubs, spears, and arrows. European guns, boats, and steel axes transiently facilitated inter-island head-hunting in the Solomon Islands in the 19th century: unlike stone axes, steel axes can behead many humans without losing their sharp edge. Similarly, European guns and horses, and European guns and slave-buyers, stimulated warfare in the North American Great Plains and in Central Africa, respectively. For each of these societies that I have just mentioned, warfare had been endemic long before European arrival, but effects of Europeans caused an exacerbation of warfare for a few decades (New Zealand, Fiji, Solomon Islands) or a few centuries (Great Plains, Central Africa) before it died out.
In other cases the arrival of Europeans or of other outsiders led instead to warfare’s end without any hint of an initial flare-up. In many parts of the New Guinea Highlands the first Europeans were government patrols that immediately ended warfare before European traders, missionaries, or even indirectly transmitted European trade goods could appear. When first studied by anthropologists in the 1950s, Africa’s !Kung bands were no longer raiding each other, although the frequency of individual murders within bands or between neighboring bands remained high until 1955. Four of the last five murders (in 1946, 1952, 1952, and 1955) resulted in the Tswana administration taking the killers off to jail, and that plus the availability of Tswana courts for settling disputes induced the !Kung to abandon murder as a means for resolving conflicts after 1955. However, !Kung oral histories report inter-band raids several generations earlier, until the time when increased Tswana contact introduced iron for arrowheads and other changes. Somehow, that contact resulted in an end to raiding long before the Tswana police intervened to arrest killers.
My remaining example comes from northwest Alaska, where formerly widespread fighting and exterminations among Yupik and Iñupiaq Inuit ended within a decade or a generation of European contact—not because of patrol officers, police, and courts forbidding war but because of other consequences of contact. The end of Yupik warfare is attributed to an 1838 smallpox epidemic that depleted the populations of several groups. The end of Iñupiaq warfare appears to have been due to the Iñupiaq chronic obsession with trade, and to their greatly increased new opportunities to trade furs to the Europeans with whom regular contact became intense after 1848: continued warfare would have been an obvious impediment to those opportunities.
Thus, the long-term effect of European, Tswana, or other outside contact with states or chiefdoms has almost always been to suppress tribal warfare. The short-term effect has variously been either an immediate suppression as well or else an initial flare-up and then suppression. It cannot be said that traditional warfare is an artifact of European contact.
Nevertheless, there has been a long history of denial of traditional warfare among Western scholars. Jean-Jacques Rousseau, already mentioned for his speculative theory of state formation not based on any empirical evidence, had an equally speculative and ungrounded theory of warfare: he claimed that humans were naturally compassionate in a state of nature, and that wars began only with the rise of states. Trained ethnographers studying traditional societies in the 20th century mostly found themselves dealing with tribes and bands that had already been pacified by colonial governments, until some anthropologists were able to witness the last examples of traditional wars in the 1950s and 1960s in the New Guinea Highlands and Amazonia. Archaeologists excavating fortifications associated with ancient wars have often overlooked, ignored, or explained them away, e.g., by dismissing defensive ditches and palisades surrounding a village as mere “enclosures” or “symbols of exclusion.” But the evidence of traditional warfare, whether based on direct observation or oral histories or archaeological evidence, is so overwhelming that one has to wonder: why is there still any debate about its importance?
One reason is the real difficulties, which we have discussed, in evaluating traditional warfare under pre-contact or early-contact conditions. Warriors quickly discern that visiting anthropologists disapprove of war, and the warriors tend not to take anthropologists along on raids or allow them to photograph battles undisturbed: the filming opportunities available to the Harvard Peabody Expedition among the Dani were unique. Another reason is that the short-term effects of European contact on tribal war can work in either direction and have to be evaluated case by case with an open mind. But the widespread denial of traditional warfare seems to go beyond those and other uncertainties in the evidence itself, and instead to involve reluctance to accept evidence for its existence or extent. Why?