The Northwest Passage

Four centuries of searching

The Northwest Passage is a series of deep channels through Canada’s Arctic Archipelago, about 1,450 km from north of Baffin Island to the Beaufort Sea above Alaska. It lies 800 km north of the Arctic Circle.^[1] Inuit have lived on and travelled its land, water and ice since time immemorial.^[2]

European explorers searched for it from 1497, when Henry VII of England sent John Cabot to look for a northwest route to Asia. Many failed and many died, including Henry Hudson, set adrift by his crew in 1611.^[1] The Norwegian Roald Amundsen finally sailed through in a converted herring boat, the Gjøa, setting out in 1903 and reaching Nome, Alaska, in 1906. The first transit in a single season was made in 1944 by Henry Larsen of the Royal Canadian Mounted Police.^[1]

Internal waters or an international strait?

Canada has held sovereignty over the Arctic Archipelago since 1880.^[1] The dispute is about the water between them. In 1985 Canada drew straight baselines around the Arctic Archipelago, marking the outer limit of what it calls its historic internal waters. Canada argues that its title rests on exploration, effective governance, and Inuit use and occupation of the waters and sea ice “as they have used and occupied the land”.^[2]

The United States argues that the passage connects the Atlantic and Pacific and so is an international strait under Article 37 of the UN Convention on the Law of the Sea, with a right of transit for every nation’s ships whether or not Canada consents. It says a strait doesn’t have to be ice-free or busy to count, and it has never accepted Canada’s historic waters claim.^[2]

Much depends on the answer. As internal waters, Canada could apply its own environmental and safety rules and bar foreign warships; as a strait, it could apply only internationally agreed standards, and there would be an international air corridor overhead.^[2] Washington worries about precedent too: conceding here could weaken its challenges to other countries’ maritime claims, such as China’s claim to the Qiongzhou Strait. Russia takes a position like Canada’s for its own Northern Sea Route.^[2]

Two voyages and an agreement

Two US voyages caused uproar in Canada: the oil tanker SS Manhattan in 1969, and the Coast Guard icebreaker Polar Sea in 1985. Neither asked formal permission, though both were coordinated with Canada along the way.^[2]

On 11 January 1988 the two governments signed the Arctic Cooperation Agreement in Ottawa. The United States pledged that its icebreakers would sail through “waters claimed by Canada to be internal” only with Canada’s consent, and both agreed that nothing in the deal affected either side’s legal position.^[3] It has been called a pragmatic “agree to disagree” arrangement, and as of 2025 the official line on both sides was unchanged.^[2]

“The Government of the United States pledges that all navigation by U.S. icebreakers within waters claimed by Canada to be internal will be undertaken with the consent of the Government of Canada.”^[3]

Melting ice, more ships

Summer sea ice has shrunk sharply since about 2000.^[1] In 2007 a record retreat opened the whole passage for the first time on record, and while it took a century to log the first 69 complete transits, the next 69 took just five years, 2006–10.^[2] In 2013 the Nordic Orion became the first large bulk carrier to make the trip, with icebreaker escort, and in 2014 the cargo ship Nunavik sailed through without one.^[1]

It’s still no shipping lane. Ice choke points, poor charts, few ports and high insurance keep most traffic local: supply ships, fishing boats, tankers, cruise ships and pleasure craft.^[2] Inuit organisations say the passage is part of their homeland, Inuit Nunangat, and that any rules for it must recognise Inuit rights and co-management.^[2]