The next familiar tactic is the raid, in which a group of warriors small enough to conceal itself, advancing under cover or at night, makes a surprise attack on enemy territory with the limited goal of killing some enemies or destroying enemy property and then retreating, but without the expectation of destroying the whole opposing army or permanently occupying enemy territory. This is perhaps the most widespread form of traditional warfare, documented in most traditional societies, such as the Nuer raids against the Dinka, or the Yanomamo raids against each other. I described Dani raids that occurred on May 10, May 26, May 29, June 8, June 15, July 5, and July 28, 1961. Examples of raids, by infantry and now also by ships and airplanes, abound in state warfare as well.
Related to raids, and also widespread in traditional warfare, are ambushes, another form of surprise attack in which the aggressors, instead of moving by stealth, hide themselves and remain in wait at a site to which unsuspecting enemies are likely to come. I described Dani ambushes that took place on April 27, May 10, June 4, June 10, July 12, and July 28, 1961. Ambushes remain equally popular in modern warfare, abetted by radar and code-breaking methods that facilitate detecting movements of enemy who are less likely to detect the ambushing party.
A traditional tactic without parallel in modern state warfare is the treacherous feast documented among the Yanomamo and in New Guinea: inviting neighbors to a feast, then surprising and killing them after they have laid down their weapons and focused their attention on eating and drinking. We moderns have to wonder why any Yanomamo group would let itself fall into that trap, having heard stories of previous such treachery. The explanation may be that honorable feasts are common, that accepting an invitation usually brings big advantages in terms of alliance-building and food-sharing, and that the hosts go to much effort to make their intentions appear friendly. The only modern example I can think of involving state governments is the massacre of the Boer commander Piet Retief and his whole party of a hundred men by the Zulu king Dingane on February 6, 1838, while the Boers were Dingane’s guests at a feast in his camp. This example may be considered the exception that proves the rule: the Zulus had been just one of hundreds of warring chiefdoms until unification and the foundation of the Zulu state a few decades previously.
Such blunt treachery has for the most part been abandoned under the rules of diplomacy which modern states now find it in their own self-interest to follow. Even Hitler and Japan issued formal declarations of war against the Soviet Union and the U.S., respectively, simultaneous with (but not before) their attacks on those countries. However, states do employ treachery against rebels whom they consider as not binding them to the usual rules of diplomacy between states. For instance, the French general Charles Leclerc had no qualms about inviting the Haitian independence leader Toussaint-Louverture to a parley on June 7, 1802, seizing him there, and shipping him to a French prison, where he died. Within modern states, treacherous killings are still carried out by urban gangs, drug cartels, and terrorist groups, which do not operate by the rules of state diplomacy.
Another form of traditional warfare without close modern parallels is the non-treacherous gathering that degenerates into fighting. Far commoner than a treacherous feast, this involves neighboring peoples meeting for a ceremony without any intention of fighting. But violence may nevertheless erupt because individuals who have unsettled grievances and who rarely encounter each other now find themselves face-to-face, can’t restrain themselves, and begin fighting, and relatives then join in on both sides. For example, an American friend of mine who was present at a rare gathering of several dozen Fayu people told me of the tension prevailing as men periodically burst out in mutual insults and explosions of anger, pounded the ground with their axes, and in one case rushed at each other with axes. The risk of such unplanned fighting breaking out at gatherings intended to be peaceful is high for traditional societies in which neighboring peoples meet rarely, revenge for grievances is left to the individual, and there is no leader or “government” able to monopolize force and restrain hotheads.
Escalation of spontaneous individual fighting into organized warfare of armies is rare in centralized state societies but does sometimes happen. One example is the so-called Soccer War of June–July 1969 between El Salvador and Honduras. At a time when tensions between the two countries were already high over economic disparities and immigrant squatters, their soccer teams met for three games in a qualifying round for the 1970 World Cup. Rival fans began fighting at the first game on June 8 in the Honduran capital (won 1–0 by Honduras), and the fans became even more violent at the second game on June 15 in the El Salvador capital (won 3–0 by El Salvador). When El Salvador won the decisive third game 3–2 in overtime on June 26 in Mexico City, the two countries broke diplomatic relations, and on July 14 the El Salvador army and air force began bombing and invading Honduras.
Mortality rates
How high is the mortality from traditional tribal warfare? How does it compare with the mortality from warfare between state governments?
Military historians routinely compile national casualty totals for each modern war: e.g., for Germany during World War II. That permits one to calculate national war-related mortality rates averaged over a century of a country’s history of alternating war and peace: e.g., for Germany over the whole of the 20th century. Such rates have also been calculated or estimated in dozens of studies of individual modern traditional societies. Four surveys—by Lawrence Keeley, by Samuel Bowles, by Steven Pinker, and by Richard Wrangham and Michael Wilson and Martin Muller—summarized such evaluations for between 23 and 32 traditional societies. Not surprisingly, there proves to be much variation between individual societies. The highest annual time-averaged war-related death tolls are 1% per year (i.e., 1 person killed per year per 100 members of the population) or higher for the Dani, Sudan’s Dinka, and two North American Indian groups, ranging down to 0.02% per year or less for Andaman Islanders and Malaysia’s Semang. Some of those differences are related to subsistence mode, with average rates for subsistence farmers being nearly 4 times those for hunter-gatherers in Wrangham, Wilson, and Muller’s analysis. An alternative measure of war’s impact is the percentage of total deaths that are related to warfare. That measure ranges from 56% for Ecuador’s Waorani Indians down to only 3%–7% for six traditional populations scattered around the globe.
For comparison with those measures of war-related mortality in traditional small-scale societies, Keeley extracted 10 values for societies with state government: one of them for 20th-century Sweden, which experienced no wars and hence zero war-related deaths, the other nine for states and time periods selected for notoriously horrible suffering in war. The highest-percentage long-term death tolls averaged over a century in modern times have been for 20th-century Germany and Russia, which reached 0.16% and 0.15% per year respectively (i.e., 16 or 15 people killed per year per 10,000 members of the population) due to the combined horrors of World Wars I and II. A lower value of 0.07% per year held for France in the century that included the Napoleonic Wars and the winter retreat of Napoleon’s army from Russia. Despite the deaths inflicted by the two atomic bombs on Hiroshima and Nagasaki, the fire-bombing and conventional bombings of most other large Japanese cities, and the deaths by gunfire and starvation and suicide and drowning of hundreds of thousands of Japanese soldiers overseas during World War II, plus the casualties from Japan’s invasion of China in the 1930s and the Russo-Japanese war of 1904–1905, Japan’s percentage war-related death toll averaged over the 20th century was much lower than Germany’s or Russia’s, “only” 0.03% per year. The highest long-term estimate for any state is 0.25% per year for the famously bloody Aztec Empire in the century leading up to its destruction by Spain.