Donald Trump reignited tensions by demanding to buy Greenland from Denmark, causing shock across Europe. In a private message, French President Emmanuel Macron wrote, "I do not understand what you are doing on Greenland,” which Trump shared publicly to embarrass Macron. Trump claims only the US can secure Greenland and seeks "immediate negotiations" without military force. NATO allies worry because Trump’s threats include military pressure on a partner nation. Belgium’s Prime Minister Bart De Wever said, "A Nato country is threatening another Nato country with military invasion." Trump also threatens tariffs on eight European countries that sent troops to the Arctic near Greenland. Starting February 1, these countries face a 10% tariff, rising to 25% by June if Greenland talks fail. Europe's leaders met in Davos and at an EU summit to discuss a response. The EU has prepared countermeasures, including tariffs on $93 billion worth of American goods like soya and bourbon, ready from February 7. The EU Parliament agreed to suspend ratifying the new EU-US trade deal made in July. French President Macron supports using the EU’s powerful anti-coercion tool called the "bazooka," which can block companies from aggressor countries in the EU market. However, some leaders like Germany’s Chancellor Friedrich Merz and Italy’s PM Giorgia Meloni prefer dialogue over harsh action. Experts warn mild responses may fail. Alberto Alemanno, EU law professor, urged a “coordinated boycott of the forthcoming football World Cup in the US” and use of the “big bazooka” against Trump’s aggressive tactics. The European Policy Centre’s Georg Riekeles said the EU can also target US digital services with retaliation. MEP Damian Boeselager believes showing strength is the only language Trump understands, saying, "We are an economic superpower." European Commission President Ursula von der Leyen called for using Europe’s “levers of power” and said, "In a lawless world," old caution must go. Yet, observers doubt if EU leaders will act decisively now. They expect tariffs only if US tariffs start February 1 and think the “bazooka” may be held back for later. The Greenland dispute has become a test of Western unity, with Trump’s actions risking cracks in NATO and EU relations.