In a 6-3 decision, the U.S. Supreme Court ruled that the International Emergency Economic Powers Act (IEEPA) does not authorize the president to impose tariffs, striking down the controversial tariffs imposed on imports from most U.S. trading partners. The ruling invalidated approximately $175 billion in tariffs already collected and prevented an estimated $1.4 trillion in additional tariff revenue over the next decade. The decision reaffirms the constitutional principle that Congress, not the executive branch, holds primary authority over taxation and trade policy. The ruling has created uncertainty in international trade negotiations, with several countries, including Japan, India, and Mexico, reassessing previously negotiated trade agreements.