The United States of America installed several military bases in Greenland. One of those bases was Camp Century, the other was the Thule Air Base where the Thule Bomb Accident of 1968 took place
The Thule Bomb Accident 1968: A Series of Catastrophic Events
Project Iceworm 1960: The Secret Nuclear Tunnels Under Greenland
In 1960, at the height of the Cold War era, the US Army developed a secret program named Project Iceworm aimed at constructing a network of movable nuclear missile launch sites beneath the Greenland ice sheet.
Project Iceworm 1960: The Secret Nuclear Tunnels Under Greenland