But Trump’s obsession with taking Greenland is the kind of existential threat to European sovereignty that, in the eyes of some European officials and diplomats who spoke to POLITICO, demands a stronger response. The most they feel they could do to placate him is commit more troops.

Trump’s threat to annex an autonomous part of Denmark has plunged NATO into an unprecedented situation: An alliance based on collective defense now faces the prospect that one member might attack another.

In addition to political resistance, Greenland’s mineral riches and strategic position would come at a steep cost for the U.S.

The ice-covered island may be strategically important, but it's unclear that it could be a commercially viable source of minerals and oil in the near future

Veteran diplomat tells CBS News Denmark "ready to cooperate" on Greenland, and he expects U.S. to abandon "anachronistic approach of colonialism" post-Trump.

President Trump and his administration are actively discussing the possibility of making an offer to purchase Greenland, the White House confirmed Wednesday. Press Secretary Karoline Leavitt said the idea is being reviewed by Trump and his national security team.

U.S. President Donald Trump has ramped up talk about bringing Greenland, a Danish territory, under Washington's control. Both Denmark and the U.S. are members of the NATO military alliance. Experts told CNBC that a U.

Greenland is 836,000 square miles of largely frozen ground northeast of Canada. So why does the White House say it "should be part of the United States"?