President Donald Trump has escalated tensions with Europe by vowing sweeping tariffs on eight allied nations backing Denmark in the dispute over Greenland. The proposed measures include an immediate 10% tariff on goods, with a warning that penalties could rise to 25% by June unless a deal is reached. The move targets key NATO allies and risks triggering a broader trade war, raising questions about alliance unity, legal authority, and the global economic fallout of the growing Greenland standoff.