The U.S. National Security Agency (NSA) used a partnership with Denmark's foreign and military intelligence service to eavesdrop on top politicians and high-ranking officials in Germany, Sweden, Norway, and France by tapping into Danish underwater internet cables between 2012 and 2014.
Details of the covert wiretapping were broken by Copenhagen-based public broadcaster DR over the weekend based on interviews with nine unnamed sources, all of whom are said to have access to classified information held by the Danish Defence Intelligence Service (Forsvarets Efterretningstjeneste or FE).
German Chancellor Angela Merkel, the then-German Foreign Minister Frank-Walter Steinmeier, and the opposition leader at the time, Peer Steinbrück, are said to have been targeted through the Danish-American pact.
Using the telephone numbers of politicians as search parameters, the report alleged that the NSA "intercepted everything from text messages to phone calls that passed through the cables on their way to and from the phones of politicians and officials."
The spying operation involved deploying a special technical software called XKeyscore in a data center located at Sandagergårdan in the city of Dragoør to search and analyze data streams flowing in and out of the internet cables. XKeyScore is a data-retrieval system that enables unlimited surveillance of people anywhere in the world, allowing the intelligence agency to track individuals, read emails, and listen in on their telephone calls and browsing histories.
German Chancellor Angela Merkel
But in 2014, following concerns that the NSA had abused the collaboration with FE to spy on targets in Denmark and its neighbors, the Danish counterpart established a secret internal working group with four hackers and analysts — under the codename "Operation Dunhammer" — to examine the partnership.
The latest round of revelations is the result of a 2015 report that the working group presented to the FE, which also found that Danish intelligence helped the U.S. agency spy on Danish foreign and finance ministries as well as a weapons manufacturer, ultimately forcing the government to suspend the head of the FE and three other officials in August 2020.
U.S. whistleblower Edward Snowden, who previously made public a trove of classified information revealing alleged tapping of the German chancellor's phone by the NSA in October 2013, accused U.S. President Joe Biden of being "deeply involved in this scandal the first time around". Germany dropped its investigation into the phone-tapping incident in June 2015 citing lack of evidence.
"There should be an explicit requirement for full public disclosure not only from Denmark, but their senior partner as well," Snowden tweeted.