Greenland security development depends on US, partner cooperation, Pentagon official says

The Pentagon is assessing investment needs for Greenland, including funding for improvements at Pituffik Space Base, shown here. (US Army Corps of Engineers)

Boosting Greenland's security development following the recent agreement between the US, Denmark, and Greenland depends on the parties' ability to cooperate on requirements and investments, according to Dale Marks, US Department of Defense (DoD) assistant secretary of Energy, Installations, and Environment.

“We're talking about concept of operations – [determining] what do we think we want to do?” Marks said on 20 October during a Defense Writers Group round table discussion.

Denmark, Greenland, and the US reached an agreement on greater American responsibility for Greenland's security, US President Donald Trump announced on 19 September in a social media post.

The agreement essentially guarantees US security access and responsibility, secured in a 1951 treaty with Denmark, but includes Greenland's consultation and input and ensures that access in perpetuity, US officials familiar with the agreement told Janes at the time.

Trump administration officials had expressed concerns about the 1951 agreement to Janes in June 2025. Specifically, they noted that Greenland was moving towards independence, and they said they were worried that, because the agreement was with Denmark without Greenlandic consultation and input, then Greenland could opt to ignore it if the Arctic island became its own country.

Trump administration officials also told Janes they were concerned Greenland could be lured by Chinese investment, giving China a foothold in a country located at a strategic chokepoint for US security in the North Atlantic and Arctic. They also told Janes they believed neither Denmark nor NATO was sufficiently resourcing Greenland's defence to ensure US security at that chokepoint.