Beyond the notion of two nations waging war together against one, all three participants in the war were somewhat equal prior to the war, but the war itself exposed a few critical factors that made it possible for Chile to defeat both Peru and Bolivia in the War of the Pacific. We will focus on different factors that had an impact on the war during the conventional phase of the war (1879-1881).

Politics and war

Before we dive deeper into the military factors, it's worth considering the political factors which in turn had an impact on the military leadership. In the two decades before the war and throughout the war itself, the three nations involved had very dramatic political turns and events. Although Chile had endured a civil war in the 1850s (and would again just 10 years after the War of the Pacific), things had remained calm in as much as "elections" proceeded and new presidents took the stage in less than savory fashions. That was not the case for Peru and Bolivia. Both countries suffered constant upheavals and this political instability had an impact on who led the nation's army into war and who the officers were who led the soldiers. Chile also suffered from this in the first months of the war, with politicians protecting admiral Juan Williams Rebolledo and general Justo Arteaga, despite their inactivity and in the case of admiral Williams, losses. Yet these generals were removed from service and replaced by generals who took the war into the heartland of Peru in the years to come. The same can not be said about Peru and Bolivia. Furthermore, Peru and Bolivia suffered several political upheaval during the war that had an impact in how the war was waged while Chile remained steady and even experienced a calm election in which a new president took the stage.

One case in particular is worth to acknowledge for the sheer eccentricity and mystery that still baffles historians today.

In response to the Chilean amphibious landing at Pisagua in November 1879 and the subsequent offensive inland to occupy the economically important province of Tarapacá, a portion of the combined forces of Peru and Bolivia were planned to be used in an offensive to catch the Chilean forces in a concentrated attack. The Peruvian force under General Buendiá was in place in Tarapacá, but the Bolivian force had to march south to join them. This is where it all went wrong. Leading the troops was none other than the President of Bolivia himself, General Hilarión Daza. Daza led 3000 men in a sixty-two miles march through some of the most inhospitable environment in the world (The Atacama desert) without proper supplies, caring little to prepare his men for the march ahead and forcing them to march at day when the sun was at its worst and without guides to lead them to their actual destination. It took the men 3 days to walk from Arica to Camarones, a march of around 50 miles and in which plenty of Bolivian soldiers died on the way due to thirst, hunger and pure exhaustion. Camarones was not the final destination. Tana, the final destination, was still 22 miles away but the soldiers would never reach it. For some reason, whether it was Daza's fear that he was about to be overthrown back home in La Paz or because, as Daza himself argued later that the president of Peru, President Mariano Prado, who had actually helped Daza planned this operation to begin with was at fault for not supplying him properly, the remaining men turned around and marched back to Arica. This did not only doom the planned offensive, leading to a Peruvian loss at the Battle of Dolores/San Francisco, but also led to the downfall of Daza's regime. He was heavily criticized for essentially defecting and both Bolivian soldiers and civilians turned on him. Daza was ultimately overthrown by the army and forced into exile in Europe.

Control of the sea

La Guerra del Pacifico, The War of the Pacific, takes its name from the Pacific ocean which played an important part in Chile's eventual victory. The military control of the Pacific was vital for several reasons. Without control of the Pacific, being able to transport troops into the contested regions would have been nearly impossible. One the first day of the war, Chilean troops occupied Antogofasta after an unexpected seaborne landing. After this date, Chile would be unable to do something similar until they had complete control of the Pacific coast, something which they wouldn't have until the battle of Angamos (October 8 1879) where Chilean ironclads, repaired and refurbished after the sacking of admiral Juan Williams Rebolledo and put in a proper naval strategy, defeated the Peruvian ironclad Huáscar that had been menacing the Chilean navy for many months. With Huáscar out of the way, Chile could now occupy Peruvian harbors and land troops wherever they wanted. Pisagua, Ilo, and Chilca all prove how vital these amphibious landings were. Since Peru and Bolivia were denied access to the Pacific, they could not take advantage of it in their military operations and that meant that they remained on the defensive throughout the conventional phase of the war. Still, this was poor solace for the troops who had to fight the war. Due to the poor infrastructure of a region such as Tarapacá, soldiers frequently had to march for days in one of the most hostile environment in the world.

But this control of the Pacific coast was also important for another reason: supply. Without any threats on the Pacific, Chile could import all supplies and weapons that they needed to wage a war on this scale and with the ever-expanding Chilean army. But they were also able to deny Peru and Bolivia the very same critical supplies. By controlling the regions of Tarapacá, Tacna, Arica, and Antofagasta, Chile was also able to deprive Peru and Bolivia of any revenue and taxes that they would have gotten from their natural resources in the area and that they could have used to pay for the war.

Logistics and organization

This denial of revenue and supplies brings us to another important point. None of the armies involved in the War of the Pacific had any sort of supply organization, general staff or even a medical organization. Out of the three, Chile had the only advantage entering the war for one reason alone: a (rough) standardization of weapons and ammunition. Bolivia and Peru had an irregular supply of weapons with a wide variety supplied to soldier which made the supply of ammunition very difficult. Logistics are vital in a war. Difficulties to supply soldiers in the field can and will lead to disaster. A supply corps was desperately needed and although Peru and Bolivia created ad-hoc solutions, Chile actually created a proper supply organization. Furthermore, while Bolivia and Peru struggled with supplying soldiers with food, water and uniforms - Chile's newly formed supply corps managed to supply soldiers moving into the interior of the Atacama desert and even produced an entirely new set of Chilean uniforms more suitable for the new environment. Although Peru had it easier than the other two countries since the majority of the war took place on its own territory (thus cutting the logistical lines), their harbors were blockaded after autumn 1879 and that meant that the advantage they had in the beginning was forfeited. Furthermore, Chile's civilian infrastructure made it capable of moving all logistics and soldiers without major issues. Despite the majority of the war taking place on Peruvian territory, the Peruvian civilian infrastructure never reached the regions in conflict.

Tactics?

There's no real indication that one soldier was better than the other. They all fought valiantly, some against terrible odds and suffered from the same environment and issues of morale. There was a difference in officers, as pointed out before, where Chile had somewhat of an advantage. Yet the only place where Chile truly had an advantage was in the quality of men in the navy which, as we have seen, made a tremendous impact on the war after good planning under the supervision of a superior admiral. However, there were no tactical or strategic brilliance by any side of the conflict. The tactics relied upon by Chilean commanders, for example, were antiquated. It was up to individual commanding officers to train their men in more modern, dispersed tactics. Upon hearing a suggestion to train their men in dispersed tactics, Diego Dublé Almeida recalls hearing the commander of the Navales battalion, Martianio Urriola, saying that: "[T]he Chilean soldier didn't need the dispersed order to win at Chacabuco and Maipú, Yungay and Calama: it was enough to be a Chilean soldier to win and they won." Tactics that had been good enough in 1818 (battle of Maipú) and 1839 (battle of Yungay) were more than enough for 1879, argued Urriola and his sentiments were widely shared amongst Chilean commanders. Recent popular history arguments that Chile employed particularly innovative strategies/tactics are disproved by the historical record.

In the end, the previously mentioned factors played a critical role in deciding the war in Chile's favor. Once Chile had gained control of the Pacific coast, they were able to hold on to the initiative and strike wherever they wanted. Yet this was not an exclusively military victory. The cooperation of the Chilean military establishment with the civilian government was paramount in deciding victory. Without the introduction of a proper logistical organization by the civilian comisario general Rafael Sotomayor it would not have been possible for the Chilean forces to move up and down the Bolivian and Peruvian coast after the defeat of the Huascár in the battle of Angamos. It goes to show that victory on the battlefield is not only reliant on how many men or ships you have on paper.