Geopolitics is not just a tool or a field of study to be applied to state policies. Little understanding and neglecting it, the academy distanced itself from geopolitics, crediting it as a discipline strictly focused on war, of little relevance, or even outdated in conceptual and theoretical terms. Losing sight of the relevance of the relationship between territory and geopolitics, the latter was restricted to a merely speculative and inert field. Contradicting this notion and building an approximation rarely performed between geography and international relations, we seek to carry out an analysis of Brazilian foreign policy from the Estado Novo to the Livro Branco de Defesa Nacional (1937 to 2012), evidencing the constancy of geopolitics as a product of the power relations between diplomacy actors and the territory. Highlighting the gaps in internationalist conceptions about the concept of territory and geography and carrying out a survey of documents from the Ministry of Foreign Affairs and other historical collections, we seek to weave the relationships between the formation of the national territory and the construction of foreign strategies of Brazilian governments, observing, in this process, not only the formation of Brazil's foreign policy but also of geopolitics built within the State. For the elaboration of this research, we used primary material present in several historical collections, among which the National Archives, the Center for Research and Documentation of Contemporary History of Brazil (CPDOC), and the historical collection of the United States Department of State. The argument built in this thesis shows not only the eminence of approaching the geographic debate to international relations but also of affirming geography as an essential science for the understanding of Brazilian foreign policy, insofar as it has the territory as an essential foundation.