The NATO security alliance that has protected Europe for decades finds itself with limited power to determine its own fate due to President Donald Trump’s desire for U.S. ownership of Greenland.

Since Trump revived his ambition to claim the semiautonomous Danish territory after the U.S. military operation to capture the Venezuelan president, NATO members have been scrambling for ideas to counter U.S. criticism that Greenland is under-protected as Russia and China take a greater interest in the Arctic and its mineral riches.

Any forcible U.S. takeover of Greenland would be an unprecedented seizure of one NATO ally’s territory by another — the nuclear-armed superpower that ​is meant to provide the ultimate security guarantee for all members.