European leaders are bracing for an all-out trade war with the U.S. once again after President Trump threatened to impose a 10% tariff on imports from from countries that oppose his demand to take control of Greenland. The potential tariff would put the U.S.-EU trade deal struck last summer in jeopardy. The agreement includes $750 billion worth of energy purchases from the U.S., $600 billion in EU investment, and billions of dollars in reduced tariffs on imports from European countries. Read