The US Navy is putting its submarines on rare public display in a message to Russia's growing undersea force

• The US Navy has announced several visits by its subs to North Atlantic ports in recent years.
• Subs are among the US's most secretive weapons, and announcements about their movements are rare.
• Their growing visibility comes as Russia's own increasingly advanced subs are getting more active.

The US Navy rarely reveals where its submarines are, but it is making those subs more visible in the North Atlantic, demonstrating their presence as US officials warn that Russian submarines are more active and carrying new weapons closer to US shores.

Since late 2020, the Navy has announced multiple visits by its submarines to Tromsø in northern Norway, the Danish-controlled Faroe Islands, and Iceland — locations that reduce the time those subs have to spend away from their operating areas, according to Vice Adm. William Houston, the commander of US submarine forces.

"We have increased activity in the Atlantic. We keep a very close eye on that, and our NATO partners and allies are absolutely critical to that," Houston said at the Sea Air Space Symposium outside of Washington DC on April 3.

For subs in the North Atlantic, access to those ports means "we can exchange people off those submarines in hours when typically it would take us days to pull into Faslane," Houston added, referring to a base in Scotland. "So it gives us an incredible opportunity and an incredible strategic position to do that."

The US Navy focused less on submarine activity in the high north after the Cold War, but its attention has increased over the past decade, as shown in its sub operations and its anti-submarine-warfare exercises.

"There was a time when we sort of backed off on that because the Russian threat" was diminished and there were higher priorities elsewhere, but the Navy "has been increasing the number of deployments they've been doing with submarines up to the high north," Bryan Clark, a former US Navy submarine officer, told Insider.

A Norwegian navy officer said in January 2018 that allied submarines were entering Norwegian waters or ports for supplies or personnel exchanges three to four times a month. Since 2020, when Norway allowed NATO subs to use a port near Tromsø, announcements of such visits appear to have increased.

In August 2020, the Navy said USS Seawolf, a West Coast-based attack sub, made "a brief stop for personnel in the vicinity of Tromso." That was followed by visits by USS New Mexico in May 2021 and USS Washington, USS Albany, USS South Dakota, HMS Ambush, and USS Newport News — all attack subs — in 2022.

The visits reflect increasing defense cooperation between Norway and its NATO allies. "Tromsø gives us a place where we can pull in submarines, fix material things, do personnel exchanges," Houston said at the April 3 event.

"Denmark just opened up Faroe Islands for our ability to conduct brief stops for personnel, which is absolutely a key position for us," Houston added. (In August 2022, the US Navy published a graphic indicating that USS Georgia, a cruise-missile sub, was in or near the Faroe Islands.)

Houston said at the event that the Navy was "working very closely" with Iceland on permission for "brief stops" there, and on April 18, Iceland's minister for foreign affairs said US subs not carrying nuclear weapons would be allowed to make "brief" stops in Iceland for supplies and crew exchanges, calling the decision part of Iceland's "policy to support increased monitoring and response capacity of Allied countries in the North Atlantic."

On April 26, the Navy said attack sub USS San Juan had made "a brief stop" for supplies and personnel off Iceland's west coast, the first such visit by a US submarine.

'We're in your backyard'

Reducing travel time has a significant impact on what subs can do at sea.

Returning to Faslane for spare parts or to disembark a crew member "could be a week-long endeavor depending on how far out you are, and we routinely miss mission time and even have to cancel missions because of stuff like that," said Clark, now a senior fellow at the Hudson Institute think-tank. "This way, you can get that guy off the boat right away or you can get those parts right away and be right back out there in a day, so it's a huge difference."

Some missions, like mapping parts of the Arctic, can be paused without much issue, but others are more time-sensitive. "If you're trying to keep track of what a Russian undersea operation is doing or some kind of Russian exercise, missing a week means you're probably going to miss the whole thing," Clark said.

Monitoring Russian submarines has become a more urgent task for NATO, and the waters between the Arctic and Atlantic oceans are vital to that mission.

To reach the Atlantic, subs from Russia's powerful Northern Fleet have to leave their bases on the Barents Sea and sail between northern Norway and the Svalbard archipelago to reach the Norwegian Sea and then through what's known as the Greenland-Iceland-UK Gap.

Those chokepoints at either end of the Norwegian Sea allow NATO forces to more easily monitor Russian submarine movements.

Russia's undersea fleet is smaller than its Soviet predecessor, but US officials and experts say it now has submarines with more advanced sensors and weapons, including land-attack cruise missiles. Of particular concern are Russia's Severodvinsk-class subs, three of which have entered service since 2013.

With a level of quietness comparable to Western attack subs and the ability to strike important infrastructure, like sea ports, from longer ranges, Severodvinsk-class subs have worried NATO officials. Russia plans to build at least nine of them, and US officials are already warning about their presence near the US.

Gen. Glen VanHerck, who is responsible for operations around North America as head of US Northern Command, told lawmakers in March that Russian submarine activity off US coasts "is absolutely increasing."

"Within the last year, Russia has also placed their Severodvinsk-class submarines in the Pacific, so now not only [in] the Atlantic," VanHerck added. "It is just a matter of probably a year or two before that is a persistent threat — 24 hours a day potentially."

Gen. Christopher Cavoli, the head of US European Command, told lawmakers this month that Russia's undersea force has "not been affected negatively" by the war in Ukraine.

"The Russians are more active than we've seen them in years, and their patrols into the Atlantic and throughout the Atlantic are at a high level most of the time, at a higher level than we've seen in years," Cavoli added.

The increasing activity and sophistication of Russia's submarines is a driving factor behind the increase in US submarine operations — and the more frequent announcements about them — in the high north. "Part of this is to make sure the Russians understand that we're doing that," Clark said.

During the Cold War, US attack subs operated in the high north to get the Soviets to keep their attack subs close by to protect their ballistic-missile subs. The goal now, Clark said, may be to show Russia "that we're in your backyard with our attack submarine so you feel like you have to keep more of your best boats at home to protect" those missile subs.

"The US Navy has obviously increased the visibility of its submarine deployments, both in the high north and in the Western Pacific, to try to affect the decision-making of potential adversaries," Clark added, "because otherwise you're not getting nearly as much benefit from the deployment."