New Delhi, Jan. 8 -- U.S. President Donald Trump's latest threats against Greenland pose a new and potentially unprecedented challenge to NATO, perhaps even an existential one, for an alliance focused on external threats that could now face an armed confrontation involving its most powerful member.

The White House says the administration is weighing "options" that could include military action to take control of the strategically located and mineral-rich island, which is a semi-autonomous region that is part of NATO ally Denmark.

Trump's renewed interest in Greenland could put at risk the entire future of NATO, which was founded in 1949 to counter the threat to European security posed by the Soviet Union during the Cold War. The allianc...