Chile is sending Argentina a formal protest note over comments by the head of the Argentine Air Force, and Buenos Aires spent Tuesday trying to put the treaties back in the window. Brigadier General Gustavo Javier Valverde, speaking Sunday on a YouTube podcast, said “Magellan, the south, the Drake, all of that is sovereignty” and that Argentina needed to “maintain a presence” there because the area is a “bioceanic key” between the Atlantic and the Pacific. He did not name Chile. Santiago heard a claim anyway.
Foreign Minister Francisco Pérez Mackenna, on an official visit to Vietnam, called Chilean sovereignty over the entire Strait of Magellan “indisputable” and grounded in the 1881 Boundary Treaty and the 1984 Treaty of Peace and Friendship. He told foreign officials to be careful with their words. Interior Minister Claudio Alvarado said there is “nothing to discuss.” Lawmakers from more than one party pushed for a protest note, arguing that silence can be read, under international law, as accepting someone else’s claim. A Magallanes deputy called it part of a pattern, not a one-off.
The legal file is not mysterious. The 1881 treaty recognized Chilean sovereignty over the strait and made it permanently neutralized, with free navigation for ships of all nations. The 1984 Vatican treaty, signed after the two countries nearly went to war over the Beagle Channel in 1978, confirmed the southern boundaries. The Drake Passage, further south, is international water between Cape Horn and Antarctica. Together, Magellan and Drake are the main alternative to Panama for ships moving between the oceans.
Argentina’s foreign ministry answered Tuesday without naming Valverde. Both treaties, it said, “remain fully in force and are considered definitive.” The statement then folded the far south into Argentina’s broader case on the Malvinas/Falklands, the South Atlantic, and Antarctica, and pivoted hard into cooperation: mutual recognition of Antarctic rights, joint protected areas, more than two decades of a Combined Antarctic Naval Patrol, and a joint marine protected-area proposal off the western Antarctic Peninsula. In 2025, Milei’s government had already told Chile in writing that a 2021 Argentine decree talking about “joint control” of the strait was a treaty error and would be replaced.
This is the first real diplomatic scrape between Milei and Chile’s President José Antonio Kast, who took office in March. The two men are politically close, and the countries share more than 5,000 kilometers of border. That is why Santiago reacted fast and why Buenos Aires was equally fast to cite the treaties. The Air Force chief still said what he said on tape. The protest note is meant to put Chile’s reading on the record before anyone pretends the comment was just colorful talk about the south.