Rarely has critical literature been able to understand the complexities of classical geopolitics, especially in terms of why it disappeared so suddenly after World War II. The contribution suggests that geopolitics was sidelined from the scientific discussion because it was seen as an ideological field of knowledge, similar to other ideological trends that were prominent in the 20th century. We will use an epistemological-spatial approach to highlight the similarities and differences between geopolitics and other ideologies of that time. The goal is not to provide a historical account, but to reflect on the reasons for the conflict between geopolitical knowledge and ideological power: a perspective that helps explain the political and intellectual decline of classical geopolitics, and sheds light on a proposal that is still relatively unknown among professionals in the field.