Donald Trump’s remark — “Do you know what their defence is? Two dog sleds” — was meant sarcastically, referring to Greenland’s deterrence capability in the event of a foreign (specifically Russian, according to the former US president) invasion.

His dismissive comment brought renewed attention to the Sirius Dog Sled Patrol, an elite unit of the Royal Danish Navy that operates with dog teams across Greenland’s frozen terrain. Heavily armed and travelling by dog sled across an island covered by ice by nearly 80%, the members of the Sirius Patrol are among the toughest special forces units in the world.

This elite Danish naval unit is trained to operate in extreme cold and complete isolation, capable of facing threats ranging from hostile forces to polar bear attacks — which, incidentally, are more common than attempted invasions. The unit could even find itself confronting American forces if Donald Trump were ever to follow through on threats of a military incursion into Greenland, a mineral-rich region of immense strategic importance to global powers such as the United States, Russia, and China.

Five-Month Patrols in Temperatures Down to –55°C

For up to five months at a time, six dog-sled teams — each staffed by just two soldiers — patrol an area equivalent in size to the United Kingdom and France combined. Each patrol consists of only two soldiers and between 11 and 15 Greenland sled dogs.

Together, they traverse ice sheets, glaciers, and fjords for months on end, ensuring Denmark’s continuous presence in the Arctic. Their mission focuses on monitoring foreign activity, supporting search-and-rescue operations, and reinforcing Danish sovereignty over the region. They operate in conditions where the sun does not rise at all during winter and temperatures can plunge to –55°C. A single mistake can be fatal, as soldiers face hunger, frostbite, and total isolation.

Although aircraft periodically drop supplies at remote depots, patrol teams often spend months without direct human contact, communicating exclusively by radio.

The soldiers undergo years of training in Arctic survival, navigation, marksmanship, emergency medicine, and even basic veterinary care. Only a handful meet the unit’s strict criteria, making Sirius one of the most selective units in Denmark’s armed forces.

Origins in the Second World War

The unit’s history begins in the summer of 1941, during the Second World War, when it was founded as the Northeast Greenland Sled Patrol. Its initial mission was to collect meteorological data critical to military planning in Europe. Greenland was a strategic battleground, as Nazi Germany had established secret weather stations to support its submarine operations.

Author Peter Harmsen has described Greenland as the “kitchen of the weather”, where systems affecting Europe are formed. Before the creation of the patrol, locating German stations was nearly impossible due to extreme cold, limited visibility, and the inability of ships and aircraft to operate effectively.

In 1943, members of the unit discovered German activity on Sabine Island, leading to an armed confrontation. Danish patrol leader Eli Knudsen was killed, becoming the unit’s first casualty. After the war, the patrol was temporarily disbanded but re-established in 1950 during the Cold War, amid concerns about Soviet activity in the Arctic. It was later renamed the Sirius Dog Sled Patrol, after Sirius, the brightest star in the night sky.

Where Tanks and Snowmobiles Cannot Reach

Today, despite satellites, drones, and artificial intelligence, Sirius remains the first line of defence in northern Greenland.

The soldiers rely on their dogs not only for transportation but also as an early warning system, thanks to their acute sense of smell and distinctive growl when detecting polar bears or hostile presence. The dogs can navigate in complete whiteout conditions and cross terrain where snowmobiles and military vehicles become immobilised.

Former Danish Rear Admiral Torben Ørting Jørgensen described Trump’s comments as a “foolish insult”, stressing that dog sleds are the result of centuries of adaptation to Arctic conditions. As he put it: “Anyone who believes they can simply seize Greenland without understanding the environment will be led to disaster.”

As melting ice turns the Arctic into a new arena of competition for mineral resources and shipping routes, Denmark has announced a new military package to strengthen Greenland’s defences. Yet in the frozen, inaccessible north of the island, the men and dogs of the Sirius Patrol remain the cornerstone of security.

And if Donald Trump means what he says, Greenland’s “dogs of war” will be there.