Greenland at Risk? Comparing US and Danish naval strength from aircraft carriers to frigates

The question of who ultimately controls Greenland has moved beyond diplomatic rhetoric into the realm of geopolitical tension. US President Donald Trump has repeatedly argued that the island is central to American national security and has said he does not rule out the use of military force to secure it. Such remarks have unsettled both Danish and Greenlandic leaders, raising wider concerns about alliance norms and international law. Meanwhile, the Danish defence ministry has earlier stated that troops would be instructed to 'shoot first and ask questions later' if US forces attempted to enter Greenland. Against this backdrop, it is essential to examine how the two countries’ militaries, particularly their naval capabilities compare in real terms.

The current legal and military framework stems from a Cold War-era 1951 agreement between Denmark and the United States. This treaty allows significant US military access to Greenland, including the right to establish bases with Danish and Greenlandic consent, a provision the US could use to expand its presence without overt conflict. Now, according to recent reports, Trump has ordered his special forces commanders to draw up a plan to invade the Arctic island.

A comparison of naval strength highlights a stark imbalance. According to the Global Firepower Index 2025, Denmark’s fleet totals around 50 vessels, while the United States maintains approximately 440 warships. The fleet difference of 390 is stark, especially considering if a war-like situation arises.

The US operates about 11 aircraft carriers including USS Gerald R Ford, USS George HW Bush and USS Dwight D. Eisenhower. An Aircraft Carrier can be simply described as 'an airfield at sea'; They are warships or naval vessels that facilitate airplanes to take off and land at sea. However, Denmark doesn't have a single aircraft carriers.

US also has 70 submarines and nine helicopter carriers to Denmark’s zero in these categories. The US Navy operates three main nuclear-powered submarine types: Ballistic Missile (SSBNs), Attack (SSNs), and Guided Missile (SSGNs), each with unique roles like nuclear deterrence, intelligence gathering or anti-ship warfare, and land-attack or special ops. Submarines are considered extremely important for a nation as they are a nation's 'insurance policy' due to their discreet yet potent operational capacity.

In these categories as well, the US maintains a commanding lead. Denmark has no destroyers or corvettes, whereas the US fields approximately 81 destroyers and 26 corvettes. Denmark does, however, operate six mine warfare vessels, compared with eight in the US fleet.

Denmark holds the advantage in a few areas, operating nine frigates and nine patrol vessels, while the US has none in these categories. Frigates are versatile warships, employed for surface warfare, escorting other vessels, surveillance and intelligence, as well as search and rescue and disaster relief operations. Patrol vessels, on the other hand, are the backbone of a nation’s maritime security, tasked with safeguarding territorial waters, monitoring shipping lanes, and policing maritime zones.

Denmark’s armed forces remain modest in size, ranking around 45th globally with roughly 20,000 active personnel. By contrast, the United States ranks first, with approximately 1,328,000 active personnel.