o declare the truth of the war in Chile, it is convenient to tell the origin of the unhappy death of Governor Martin Garcia de Loyola, because it was the beginning of all subsequent events in that kingdom. ...) Having his government in the span of five years reduced most of that kingdom to the false peace its natives were accustomed to, for which he was equally content and deceived, it happened that on the way to Angol, accompanied by more than forty captains, he reached a valley called Curabala during the night, where they assembled their tents and released their horses, and went all to sleep, without the distrust they should have had of enemies or even of friends; because our friends are no less suspicious in that land than our sworn enemies; and going through that valley by chance were about one hundred and fifty Indians from the province of Puren, who were on that road to steal from some convoys of supplies that used to go from Concepcion to Imperial. They saw the horses grassing, and then found out that the Governor was sleeping there. ...) The Indians, seeing that they were invited by such timely occasion to such a famous deed (to which they could only aspire because there was no single sentinel on guard duty), and having had a council on whether to charge against those asleep, resolved to do it, and easily scattered throughout the tents, went into them at the same time in a sudden assault, and without much resistance took their lives; and since among the tents the Governor's was the biggest, he met his cruel executioners when they finally entered, and they took his life with a thousand wounds. They found him standing and with his chain mail in his hands because he must have awakened hearing some noise. ...) From the Governor's death, which happened in December of the year fifteen ninety-eight, a general uprising resulted, which was the beginning of the biggest losses the Spanish have had in Chile; for all the Indians rebelled, and they devastated the cities of Valdivia, Imperial, Villa Rica, Osorno, and Infantes de Angol, and the fierce barbarians committed great amounts of cruelty, ravage and bloodshed like it was never seen in any attack or assault by the angriest and most offended of enemies of the world: for they did not spare any gender, age, religion or sacred thing (Gonzalez de Najera, 1614a) (1). This was the second time the "Indians" known as Mapuche (2) killed the highest Spanish authority in Chile, and the destruction of the above mentioned cities meant that Spain had lost more than half of its Chilean colony's settlements. The "Disaster of Curalaba" and the "Destruction of the Seven Cities," as the events came to be known, amounted to the near loss of a colony due to indigenous warfare--an unparalleled occurrence in the history of the Spanish colonies in the Americas (Goicovich, 2006; Villalobos, 1995). These events were a watershed in the conflict known as the Arauco War (1536-1883) between Spanish colonizers and Mapuche warriors. Eventually, a frontier was set up on the Bio-Bio River between the Spanish colony of Chile in the north and the Mapuche-controlled territory in the south. The Mapuche were independent until 1883, when the Chilean and Argentine armies conquered their territory (Navarro, 1909).
Why where the Mapuche able to fend off Spain? There is a general consensus among historians that when the first Spanish explorers arrived in Chile, the Mapuche were a seminomadic hunter-gatherer society (3) . How were the Mapuche successful in resisting conquest when larger, more complex societies like the Incas and Aztecs quickly succumbed? (4) Was it something specific to the Mapuche as a society or military opponent, that made them prevail over a more powerful, better-equipped enemy?
This article argues that the Arauco War can be reasonably understood as an asymmetric war, this is, a war in which one of the sides (Spain) is substantially stronger than the other (the Mapuche). It evaluates two theories from Political Science that seek to explain outcomes in asymmetric warfare in the light of historical and anthropological evidence from the Arauco War. The article divides the war roughly into two periods--the initial one, where the Spanish easily prevailed, and the later one, where the Mapuche triumphed--and uses the method of comparative historical analysis to tease out the factors that affected the outcome of the war in each period (5) . It concludes that the Mapuche prevailed because they were able to change their initial, frontal war tactic to something akin to guerrilla warfare, and that the Spanish could not solve the information problem needed to triumph due to cultural differences between the two factions.
This question does not only concern a specific ethnic group from a distant corner of South America three hundred years ago: answering how the Mapuche prevailed over the Spanish refers to a broader debate on what determines outcomes in asymmetric conflicts. Indeed, analyzing the Arauco War as an asymmetric conflict does only shed light on why the Mapuche won. More importantly, applying theories of asymmetric warfare to the colonization of the Americas explains how the Spanish were able to quickly conquer millions of people with a handful of soldiers but failed to do so in particular cases. As insurgents on the weaker side of a conflict have become more likely to win wars over time (Arreguin-Toft, 2001; Lyall & Wilson, 2009), answering the question presented in this paper had never been so pressing as it is today.
THE ARAUCO WAR AS AN ASYMMETRIC AND COUNTERINSURGENCY CONFLICT
The Arauco War was a series of conflicts between the Spanish Empire and the Mapuche of central-southern Chile. Even though it occurred hundreds of years ago, the conflict has been well described by historians (Armond, 1954; Bengoa, 2008; Ferrando Keun, 1986; Gascon, 2007; Villalobos, 1995; Villalobos, Aldunate, Zapatero, Mendez Beltran, & Bascunan, 1982), ethnohistorians (Faron, 1960; Jones, 1994) (6) , and anthropologists (Brand, n.d.; Goicovich, 2007; Leon, 1983; Padden, 1957; Zavala, 2008). Moreover, there are plenty of primary sources written from the Spanish side that have survived to this day (Boccara, 2007, pp. 416-418).
The war is conventionally thought to have started quickly after the Spanish entered what is now known as Chile in 1536 with the battle of Reynoguelen, and to have ended in 1883 when Chile and Argentina conquered the Mapuche territory. Was the war actually so impossibly long? In recent decades, historians and ethnologists have argued against the traditional dates of the war (Villalobos, 1995). Villalobos claims that the conflict had a warring stage (1536-1655) and a peaceful stage (1655-1883) (Villalobos et al., 1982, p. 12). Boccara, on the other hand, argues that the Spanish were never peaceful towards the Mapuche but interacted with them in two different ways: by imposing their sovereignty over them (1545-1641), and by trying to civilize them through conversion to Catholicism (1641-1810) (Boccara, 2007; Foerster, 1996). At any rate, there is a general consensus that the so-called Arauco War was a long, violent conflict at least in its initial phase (mid-1500s to mid-1600s).
The Arauco War was a clash between unequal opponents. Although Spanish soldiers were always less numerous than their Mapuche counterparts, the Europeans had a decisive technological advantage given by the use of horses, metal, and gunpowder, which were unheard of in the Americas prior to their arrival (Salas, 1950) (7) . Also, hundreds and sometimes thousands of yanaconas or indios amigos ("friendly indians") soldiers and auxiliaries accompanied the Spanish to war (Villalobos, 1995, p. 47). These native allies were initially brought from Peru and later on from the Spanish-controlled area of Chile (8) . The Mapuche also suffered a demographic catastrophe that weakened them as soon as they encountered the Spanish: like all other Native Americans peoples, the Mapuche had no immune protection against the diseases brought by conquistadors; it is estimated that epidemics killed up to eighty percent of their population (Villalobos, 1995, p. 46) or that it went from one million people to less than 150,000 due to diseases (Bengoa, 2008, p. 287). Although the Spanish were initially victorious in their conquest (Bengoa, 2008, pp. 245-287; Ferrando Keun, 1986; Villalobos, 1995, p. 47), the abovementioned Disaster of Curalaba was the tipping point of the war (Villalobos, 1995, p. 43). It is widely accepted that the Mapuche adopted insurgency tactics as the war progressed, (Bengoa, 2008, pp. 249-251; Ferrando Keun, 1986; Gascon, 2007, pp. 45-53; Villalobos, 1995, p. 47) and ultimately came out victorious out of this century-long conflict.
The Arauco War was both an asymmetric and counterinsurgency conflict. The Mapuche were relatively numerous but faced a stronger opponent aided by technology and Native American allies. It was also a long-lasting conflict that ultimately resulted in Mapuche victory thanks to the guerrilla tactics they adopted.
How can the outcome of the Arauco war be explained? Historians and anthropologists have already begun to tackle this question. Overall, the classical argument is that complex societies, being more hierarchical, are easier to conquer once their rulers and elites are eliminated, coopted or absorbed (Cruz, 2010; Villalobos, 1995, p.47). This explanation is nevertheless insufficient to explain why most tribal societies did not resist Spanish conquest but the Mapuche did.
Several non-mutually exclusive explanations have been presented for the Mapuche case. For example, Guillaume Boccara (Boccara, 1999, 2007) argues that Mapuche society was inherently open to external influences and was able to assimilate and change to meet the demands of war against Spain (Boccara, 2007, pp. 191-193) (9) . Similarly, to Boccara, the explanation offered by Agustin Cruz...