A transatlantic storm is brewing over Greenland. U.S. President Donald Trump has threatened steep tariffs on eight European countries, starting at 10 percent in February and rising to 25 percent in June, unless a deal is reached over U.S. control of the Danish territory. He has also declined to rule out the use of force, prompting sharp warnings from Copenhagen and a scramble in Europe over how to respond without escalating into a trade war or a security crisis. EU leaders are now holding urgent talks on sovereignty, deterrence, and possible economic countermeasures. What's driving the U.S. push to take Greenland? How will Greenland annexation impact relations across the Atlantic?