Resumen: During the nineteenth century, Chile and Argentina had several border disputes, both over the Strait of Magellan and Patagonia, which concluded with the Boundary Treaty of 1881. However, these problems emerged again in the austral zone and increased tension in the 1890s, when nationalism and the arms race were mixed up with the boundary issue. Therefore, our research question is: ¿Why did the Chilean- Argentinian dispute increase if there were a treaty and a protocol in force during that decade? For this, the objectives are to: 1) evaluate unresolved limit points between both states; and 2) comprehend the nationalism and arms race atmosphere of that period. A methodology of document source analysis using archives, books, period press, and a historical-geopolitical approach within a defined time frame (1892-1999) will be utilized in this study. The results aim to demonstrate that both states, despite their agreements, sought to hasten the resolution of controversies by engaging not only state institutions but also society as a whole.