In 1968, when this writer published "Innocent Passage in the Arctic," Canada had yet to assert its sovereignty over the Northwest Passage. It has since done so by establishing, in 1985, straight baselines around the whole of its Arctic Archipelago. In August of that year, the U. S. Coast Guard vessel Polar Sea made a transit of the Northwest Passage on its voyage from Thule, Greenland, to the Chukchi Sea. Having been notified of the impending transit, Canada informed the United States that it considered all the waters of the Canadian Arctic Archipelago as historic internal waters and that a request for authorization to transit the Northwest Passage would be necessary. The United States refused to make such a request, taking the position that the Northwest Passage was an international strait. As a result, the two governments agreed that the crossing of the Polar Sea would take place without prejudice to their respective legal positions.
Canada's Sovereignty Over the Northwest Passage,
Mich. J. Int'l L.
Available at: https://repository.law.umich.edu/mjil/vol10/iss2/10