sentences:  The Danish parliament commissioned a report from the Danish Institute of International Affairs (DUPI) to determine the history of United States nuclear overflights of Greenland and the role of Thule Air Base in this regard.When the two-volume work was published on 17 January 1997 it confirmed that the nuclear-armed flights over Greenland were recurrent, but that the United States had acted in good faith.The report blamed Danish Prime Minister H. C. Hansen for intentionally introducing ambiguity in the Danish–U.S.