The U.S. Supreme Court has ruled that many of Donald Trump's tariffs, imposed under a 1977 emergency law, are illegal, marking a significant defeat for the former president. The court found that while the law allows presidential action in national emergencies to regulate foreign trade, it does not authorize the imposition of tariffs. This decision affects tariffs on dozens of trading partners, including the European Union, and those based on arguments of trade imbalances or national security concerns like combating drug trafficking and illegal migration. The ruling, a 6-3 majority decision, does not affect tariffs on specific products like steel, aluminum, and automobiles, which were enacted under a different legal framework. The court did not set a deadline for the removal of the tariffs, leaving the administrative process and potential refunds to the relevant authorities, with Trump vowing to pursue alternative legal avenues for imposing new tariffs.