U.S. Supreme Court blocks Trump’s global tariffs, opening new uncertainty

The U.S. Supreme Court ruled that President Donald Trump exceeded his authority in imposing global tariffs under a national emergency law.

In a six-to-three decision, the Court held that the Executive Branch could not invoke the International Emergency Economic Powers Act (IEEPA) to impose broad reciprocal tariffs without clear authorization from Congress.

The ruling removes the legal basis for much of the tariff package announced on April 2, 2025 — dubbed “Liberation Day” — which had established a minimum 10% duty on most imports. However, it does not affect specific tariffs applied to certain countries or products.

Hours later, Trump announced a new 10% global tariff based on other legal provisions — Sections 232 and 301 — which allow duties to be imposed on grounds of national security or unfair trade practices. The president defended his authority to act without congressional approval and sharply criticized the Court’s decision.

“Following intense negotiations after Liberation Day, the average tariff rate faced by countries selling into the United States had stabilized at around 15%. The Supreme Court’s decision has — in theory — reduced that typical rate to less than half. But it remains above 6% — roughly three times the typical rate at the start of 2025 — due to tariffs imposed under other pretexts,” explained Dharshini David, Deputy Economics Editor at BBC News.

The ruling introduces a new layer of uncertainty in international trade. Although the average tariff rate had declined after subsequent negotiations, the real impact of the decision — and of the new announcement — will depend on how they are implemented and on potential further legal challenges, as doubts persist over the effectiveness of tariff policy in reducing the U.S. trade deficit.