(CNN) Russia is amassing unprecedented military might in the Arctic and testing its newest weapons in a region freshly ice-free due to the climate emergency, in a bid to secure its northern coast and open up a key shipping route from Asia to Europe.
Weapons experts and Western officials have expressed particular concern about one Russian 'super-weapon,' the Poseidon 2M39 torpedo. Development of the torpedo is moving fast with Russian President Vladimir Putin requesting an update on a "key stage" of the tests in February from his defense minister Sergei Shoigu, with further tests planned this year, according to multiple reports in state media.
This unmanned stealth torpedo is powered by a nuclear reactor and intended by Russian designers to sneak past coastal defenses -- like those of the US -- on the sea floor.
The device is intended to deliver a warhead of multiple megatons, according to Russian officials, causing radioactive waves that would render swathes of the target coastline uninhabitable for decades.
In November, Christopher A Ford, then assistant secretary of state for International Security and Non-Proliferation, said the Poseidon is designed to "inundate U.S. coastal cities with radioactive tsunamis."
Experts agree that the weapon is "very real" and already coming to fruition. The head of Norwegian intelligence, Vice Admiral Nils Andreas Stensønes, told CNN that his agency has assessed the Poseidon as "part of the new type of nuclear deterrent weapons. And it is in a testing phase. But it's a strategic system and it's aimed at targets ... and has an influence far beyond the region in which they test it currently." Stensønes declined to give details on the torpedo's testing progress so far.
Satellite images provided to CNN by space technology company Maxar detail a stark and continuous build-up of Russian military bases and hardware on the country's Arctic coastline, together with underground storage facilities likely for the Poseidon and other new high-tech weapons. The Russian hardware in the High North area includes bombers and MiG31BM jets, and new radar systems close to the coast of Alaska.
The Russian build-up has been matched by NATO and US troop and equipment movements. American B-1 Lancer bombers stationed in Norway's Ørland air base have recently completed missions in the eastern Barents Sea, for example. The US military's stealth Seawolf submarine was acknowledged by US officials in August as being in the area.
A senior State Department official told CNN: "There's clearly a military challenge from the Russians in the Arctic," including their refitting of old Cold War bases and build-up of new facilities on the Kola Peninsula near the city of Murmansk. "That has implications for the United States and its allies, not least because it creates the capacity to project power up to the North Atlantic," the official said.
The satellite images show the slow and methodical strengthening of airfields and "trefoil" bases -- with a shamrock-like design, daubed in the red, white and blue of the Russian flag -- at several locations along Russia's Arctic coast over the past five years. The bases are inside Russian territory and part of a legitimate defense of its borders and coastline. US officials have voiced concern, however, that the forces might be used to establish de facto control over areas of the Arctic that are further afield, and soon to be ice-free.
"Russia is refurbishing Soviet-era airfields and radar installations, constructing new ports and search-and-rescue centers, and building up its fleet of nuclear- and conventionally-powered icebreakers," Lt. Col. Thomas Campbell, a Pentagon spokesman, told CNN.
