This article analyzes the dispute over the northern part of Antarctica, particularly the Antarctic Peninsula, involving Argentina, Chile, and the United Kingdom, as well as Brazil’s sovereign claim, from 2012 to 2022 through the lens of classical geopolitics. It is grounded in a documentary review of treaties, state declarations, specialized literature, and press releases. Employing a qualitative and comparative methodology, the text delineates events between 1938 and 1959, explicating territorial claims and the Antarctic Treaty, which has preserved geopolitical stability until recently when new technological, environmental, and geopolitical challenges emerged. The article posits that these national territorial assertions render the notion of Antarctica as a Common Heritage of Humanity untenable.