Carlos Camacho Arango has written a thorough and engaging narrative about the bizarre conflict that took place between Peru and Colombia in the 1930s. He wants to address two questions in this book: what happened on the Peru–Colombia border between 1932 and 1933; and what military life was like in both countries before the hostilities began. He succeeds in this endeavour. His meticulous reconstruction of the events offers a detailed insight into how these two countries experienced the conflict.

The conflict began when a small group of Peruvian soldiers, led by a lieutenant and an engineer, invaded the port city of Leticia in September 1932. Leticia had been in Peruvian territory but became Colombian after the Salomón–Lozano Treaty (1922). The treaty granted Colombia a narrow corridor between the Putumayo and Amazon rivers (the Amazonian Trapeze); Leticia was in that corridor. The city's official transfer to Colombia took place in 1930. When the hostilities began in 1932, most people living in Leticia were Peruvian citizens who still maintained close relationships with the Peruvian communities at the other side of the border. After the Peruvian occupation of Leticia, Colombia's strategy was to launch a pre-emptive attack against the Peruvian military stationed on the Putumayo River, several miles away from the territories in dispute.

Camacho argues that the conflict was a consequence of the personal ambitions of the young men who led the invasion, the larger Peruvian context which exacerbated tensions between the cities of Lima and Iquitos, as well as an international scenario in which military elites had to transfer national borders from the abstraction of a map to the reality of terrain and people. For the author, this was an international conflict because both countries mobilised their professional armed forces and their secretaries of foreign affairs. At the same time, this was also a conflict between Colombia and the Peruvian elites in the Amazonian region of Loreto. The initiators of the conflict were originally from Loreto, the majority of soldiers deployed to the border were also from Loreto, and they did not support President Sánchez Cerro because he had not revised the Salomón–Lozano Treaty.

The book has an interesting structure. It is divided into 13 chapters. The odd-numbered chapters provide a detailed chronological examination of how the conflict evolved between September 1932 and June 1933. The even-numbered chapters provide a larger analysis of the military culture that shaped both countries’ militaries in the twentieth century until the beginning of the crisis. The reader can decide how to read the book, either focusing on the narrative first and the analysis later, or reading each chapter consecutively.

In the odd-numbered chapters, we learn, for example, that the leaders of the invasion had strong connections with the elites from Loreto, they tried to redress regional demands with the occupation and they did not necessarily represent the interests of Peru's central government. As the weeks passed by, however, Sánchez Cerro changed his mind and decided to support the occupation of Leticia. Camacho states that the press in both countries covered the conflict differently. Whereas in Colombia newspapers gave wide coverage to the events on the border, in Peru the conflict did not receive much attention from the media because of state censorship. People in Lima were also generally uninterested because they did not support Sánchez Cerro. Both armies experienced serious communications and logistics problems: their chains of supply did not work effectively; the troops were not issued complete uniforms, sometimes soldiers were even barefoot; and towards the end of the hostilities, in May 1933, many soldiers from both sides had fallen sick.

The even-numbered chapters provide an analysis of the cultural traditions behind the militaries involved in the crisis. Both Colombia and Peru enjoyed, directly or indirectly, a transfer of European military traditions. Peru hired French military missions and Colombia hired Chilean missions trained by the Germans. It also hired a Swiss mission in the 1920s. Camacho states that the educational levels in both armies were deficient. One big difference, however, was that the officer corps in Peru had more men with indigenous or mestizo backgrounds. In Colombia, the officer corps was white, and related to the whiter middle classes. This difference was rooted in a practice that came all the way from the French tradition in Peru, which allowed non-commissioned officers – the senior sergeants, usually from more popular and indigenous backgrounds – to become commissioned officers if they had several years of military experience and if they passed their exams at the Chorrillos Military School. That measure was impossible in Colombia; non-commissioned officers could not become officers. Another difference was that in Colombia the military were not as involved in politics as in Peru. During the Conservative Hegemony (1884–1930) in Colombia, the military was not a destabilising force, was not attacked by conservative politicians and only exceptionally was used in repressing popular protest. In Peru, on the other hand, the military carried out several attempts at military intervention and in the 1920s it was targeted by President Augusto Leguía, who saw in this institution a constant threat to his regime. By the beginning of the conflict in 1933, the Peruvian Army displayed more cohesion than its Colombian counterpart because it had a collective internal enemy to fight against: the Partido Aprista Peruano (Peruvian Aprista Party, PAP). This political organisation, which was wrongly labelled as communist, was a larger threat than the Colombian military.

This strange conflict, in which there was no official declaration of war between the two countries, came to an end when Sánchez Cerro was assassinated. His successor, General Óscar R. Benavides, looked for a peaceful resolution and returned Leticia to Colombia. Several Colombian and Peruvian lives were lost in the conflict and, whereas Colombians remember it as a war, in Peru it is rarely remembered. This is probably one of the greatest strengths of the book: that we are constantly reminded that any type of confrontation should always be examined from both sides.