U.S. Supreme Court strikes down Trump’s “illegal” global tariffs

The U.S. Supreme Court on Friday struck down a broad set of global tariffs imposed by President Donald Trump, ruling that he exceeded his authority by using emergency powers to unilaterally levy sweeping trade taxes.

In a 6–3 decision, the court held that Congress — not the president — has the constitutional authority to impose tariffs, and that the International Emergency Economic Powers Act (IEEPA) does not grant the executive branch such expansive powers.

In its ruling, the court said IEEPA “does not authorize the President to impose tariffs.”

Addressing the administration’s interpretation of the statute, the majority wrote: “[T]he Government reads IEEPA to give the President power to unilaterally impose unbounded tariffs and change them at will. That view would represent a transformative expansion of the President’s authority over tariff policy.”

The decision represents a rare check on Trump’s aggressive use of executive authority and sets new limits on how far presidents can go in reshaping trade policy without congressional approval.

A Major Blow to Trump’s Trade Agenda

Trump introduced the tariffs in phases beginning in February 2025, invoking IEEPA on the grounds that drug trafficking and the U.S. trade deficit constituted national emergencies. In April, he expanded the measures, imposing levies ranging from 10% to 50% on goods from nearly every country in the world, including Nigeria.

The president had argued that tariffs would increase government revenue, encourage Americans to buy domestic goods and reduce the U.S. trade deficit. He has previously described foreign trade partners as having “cheaters” and “pillaged” the United States.

Before the ruling, Trump warned that a decision curtailing his tariff powers would be an “economic and national security disaster” with “catastrophic” consequences.

The Supreme Court majority was unmoved. Congress, the justices held, did not delegate such sweeping tariff authority under the 1977 emergency law.

What Happens Next?

The ruling invalidates tariffs imposed under IEEPA but does not affect sector-specific levies on steel, aluminium, lumber and automobiles introduced under Section 232 of the Trade Expansion Act of 1962 on national security grounds.

The decision also leaves unanswered how the government should handle refunds for businesses that paid the now-invalidated tariffs.

In dissent, Justice Brett Kavanaugh wrote: “The Court says nothing today about whether, and if so how, the government should go about returning the billions of dollars that it has collected from importers.”

Kavanaugh also raised concerns about the implications for trade agreements reached while the tariffs were in effect, noting that they had played a role in advancing deals worth trillions of dollars.

The Trump administration has previously indicated it could rely on alternative statutory authorities to reimpose similar tariffs if struck down.

“We’ll figure something out,” Trump said before the judgment.

Market Reaction

Wall Street responded positively, though cautiously. The S&P 500 rose about 0.45%, the Dow Jones Industrial Average gained roughly 0.07%, and the Nasdaq climbed 0.42% in early trading. Bond yields edged higher, while gold and silver briefly dropped before stabilizing.

Although the ruling could, in theory, more than halve the average tariff rate facing U.S. trading partners, analysts note that many importers have already adjusted supply chains in response to earlier levies.

For countries such as Nigeria — which were subject to the broad April tariffs — it remains unclear how quickly the ruling will translate into practical trade changes.