Supreme Court Strikes Down IEEPA Tariffs 6-3

The US Supreme Court ruled 6-3 that the International Emergency Economic Powers Act (IEEPA) does not authorize the executive branch to impose tariffs — striking down most of the 2025 tariff regime built on IEEPA authority. Markets rallied on the ruling as supply chain disruptions were expected to ease. The ruling created immediate uncertainty about the legal basis of US trade policy and the administration's response.