Until recently, Danish governments insisted that the United States adhered to Denmark's non-nuclear policy. The policy prohibits nuclear weapons on Danish territory including Greenland and the Faroe Islands. Yet during the 1990s, documents declassified and released in the United States under the Freedom of Information Act revealed that U.S. Strategic Air Command bombers armed with nuclear weapons overflew Greenland on a daily basis for most of a decade between 1958 and 1961. The political scandal that followed these disclosures lasted five years and was called Thulegate.

One of the bombers crashed on the ice off Thule Air Base in January 1968, triggering suspicion and accusations that Denmark's nuclear ban was routinely violated. Both U.S. and Danish government officials insisted at the time, however, that the aircraft had approached the area because of an emergency and that it had not been in Greenland airspace prior to the accident. The declassified documents, however, revealed that not only had the ill-fated bomber overflown Greenland prior to the accident, it had been loitering right above Thule Air Base as part of a top-secret mission to monitor the important BMEWS-radar, a vital element in U.S. nuclear war planning.

The disclosure, combined with pressure by former Thule-personnel who feared they suffered from illnesses caused by the contamination from the 1968-crash, prompted the Danish government to conduct an internal review of its records. The review uncovered documents that not only confirmed a violation of the non-nuclear policy but also could serve to explain why. The result of the review was a four-page report presented to the Danish parliament in June 1995. The report not only confirmed the overflights, but concluded that the United States had acted in good faith. The report put the blame on the late Danish Prime Minister H. C. Hansen, who during a 1957 meeting with the U.S. Ambassador had refrained from stating Danish non-policy when asked if Denmark wanted to be informed in case the United States decided to deploy nuclear weapons in Greenland. In doing so, the report concluded, Hansen gave the United States a tacit go-ahead.

Shortly after the report was released, U.S. Defense Secretary William Perry visited Denmark. After meeting with Perry, Danish Foreign Minister Niels Helveg Petersen assured the press that while nuclear weapons had overflow Greenland, it was certain that no nuclear weapons had ever been deployed on the ground. Yet only a few days later, Petersen received a letter from the U.S. government which informed that an internal investigation showed that nuclear weapons had in fact been deployed on the ground. Deeply embarrassed and faced with a major scandal, the Danish government decided to make the information public. A semi-independent investigation was commissioned that was given access to previously declassified documents from the Danish archives.

Although the U.S. government declined to grant any special declassification favors to the Danish investigation, the available information provides sufficient information to outline the extent of the U.S. deployment of nuclear weapons in Greenland. This is based on the following five bodies of documents:

1. The 1995 letter from the U.S. government to the Danish government confirming nuclear deployments in Greenland
2. The overflights under the U.S. Airborne Alert Indoctrination Program
3. The 1995-1997 semi-independent investigation by the Danish Institute of International Affairs
4. The History of the Custody and Deployment of Nuclear Weapons: July 1945 through September 1977
5. The nuclear deployment list from Strategic Air Command's 1958 History.

As a result of the information released in the many cases described above, it is possible to detail the deployment of U.S. nuclear weapons in Greenland: