The Glossary
IEEPA
The 1977 emergency-powers statute behind the 2025 "fentanyl" and reciprocal tariffs.
Definition
The International Emergency Economic Powers Act empowers the president to regulate commerce during declared national emergencies. The second Trump administration used it to impose a 10% tariff on Chinese goods in February 2025 — justified by fentanyl precursor flows — then doubled it to 20% in March, and layered the April "reciprocal" tariffs on the same footing. IEEPA had never before been used to impose broad tariffs, and litigation over that novelty is among the era's unresolved legal questions.
Why it matters
IEEPA tariffs can be imposed and modified by executive order within days — which is exactly how duties swung from 145% to 30% and back between April and November 2025.