For most of history the Arctic was a frozen ceiling that closed the map. That is no longer true. Summer sea-ice has shrunk by roughly 40% since 1980, opening shipping routes that cut weeks off Asia–Europe voyages and exposing an estimated 13% of the world's undiscovered oil and 30% of its undiscovered gas. Eight countries border the Arctic — five of them NATO members, plus Sweden and Finland joining after 2022, and Russia. What used to be a scientific curiosity is now the newest theatre of great-power competition, with fewer rules and thinner militaries than any other.
The Greenland–Iceland–UK gap is the maritime corridor Russian submarines must transit to reach the open Atlantic. During the Cold War it was ringed with sonar, patrol aircraft and Norwegian listening posts; after 1991 much of that infrastructure was quietly dismantled. Since 2014 it has been rebuilt at speed: US P-8 Poseidons rotating through Iceland, a reopened Keflavik base, and new Norwegian F-35s at Ørland. The gap is the reason Greenland is not just a talking point but a NATO asset — and the reason Moscow's Northern Fleet spends a lot of time practising how to get past it.
Roughly a fifth of Russian GDP and a quarter of its exports come from north of the Arctic Circle. Moscow has responded like a country that knows this: dozens of reopened Soviet-era bases, a new generation of icebreakers (the only serious civilian fleet in the world), coastal S-400 batteries, and the Northern Sea Route marketed as a sovereign Russian waterway. The Arctic is the one theatre where Russia still has clear conventional overmatch — and where the war in Ukraine has made Western pushback both more urgent and more expensive.
As Canadian Arctic ice thins, the Northwest Passage through the archipelago becomes navigable for more of the year. Ottawa insists these are Canadian internal waters. Washington quietly insists they are an international strait through which any vessel — including a Chinese icebreaker or a Russian submarine — has the right of innocent passage. The two closest allies on Earth have papered over the disagreement for fifty years. As traffic rises, the paper is starting to tear.
The Arctic holds an estimated 90 billion barrels of oil, 1,670 trillion cubic feet of gas, and enormous deposits of nickel, rare earths and uranium. It also has about four million residents, roughly a tenth of them Indigenous — Inuit, Sámi, Nenets, Chukchi and others whose homelands were divided by borders drawn far to the south. The Arctic Council was set up to give them a permanent seat at the table. Russia's suspension after 2022 has left that table half-empty, and increasingly it is southern capitals — not northern communities — that decide what happens on top of the world.