The Supreme Court cast aside the bulk of President Trump's sweeping tariffs Friday, obliterating a canon of his economic strategy in ruling that his use of an emergency statute to remake global trade was unlawful. The decision invalidates what the Trump administration called the president's most significant economic and foreign policy initiative of his second term, a result Trump has warned could foist financial ruin upon the United States. The justices rejected Trump's expanded use of the International Emergency Economic Powers Act (IEEPA) in imposing tariffs on nearly every country. The 1970s-era law allows the president to "regulate" imports when necessary to respond to national emergencies that pose an "unusual and extraordinary" threat.