On August 29, a U.S. Court of Appeals for the Federal Circuit ruled that tariffs imposed under the International Emergency Economic Powers Act (IEEPA) exceeded the president’s authority and were issued illegally.

The IEEPA allows the president to declare a national emergency to address “unusual and extraordinary” threats to the nation’s security, foreign policy, or economy. The court, however, found that the IEEPA does not grant the authority to impose tariffs.