The earliest and brightest of the leading lights of socialism was the cosmopolitan intellectual Gustavo Navarro, who took the public name Tristán Marof. His time in Europe in the 1920s radicalized him, and in 1926, just before his return to Bolivia, he published The Justice of the Inca, a stirring case for revolution in Bolivia and Latin America that found common ground between socialism and indigenismo. Like the heterodox Peruvian Marxist José Carlos Mariátegui, whom he met in 1927, Marof sought to root socialism in Andean soil. He was an early and prominent advocate for nationalization of the mines and for agrarian reform to overthrow what he saw as the feudal order in the countryside. This program gained hold on the left, in the labor movement, and among military veterans in the aftermath of the Chaco War, and the Revolutionary Nationalist Movement (mnr) would implement it in the revolution of 1952.

While in exile in northern Argentina in the 1930s, Marof became a leading critic of the Bolivian government’s war against Paraguay, and he formed the Revolutionary Workers Party (por), of Trotskyist orientation. The Tragedy of the Altiplano, his brilliant polemic against the old regime, the rosca, the domestic influence of foreign oil companies, and the Chaco War, came out in 1935. While Marof himself held a left-nationalist position, he argued that the Bolivian and Paraguayan governments were cynically exploiting nationalist sentiment to the detriment of working-class soldiers who fought in the arduous conditions of the Chaco and to the benefit of foreign interests, especially Standard Oil Company. While historians have since discounted the assumptions that the war was promoted by oil companies and that the Chaco territory in dispute contained significant oil reserves, these were common notions at the time in the popular press. Marof’s most famous work concluded with this open letter to the Bolivian proletariat.