Fact check: Are the tariffs in place illegal?

1. A federal court’s blunt ruling that reshapes the legal framing of the tariffs

A U.S. Court of Appeals concluded in a September 2025 decision that the President exceeded statutory authority by imposing most of the tariffs under the International Emergency Economic Powers Act, finding that Congress—rather than the President—controls tariff and tax powers in this context; the court nevertheless permitted the measures to stay temporarily in force through mid‑October 2025 pending further proceedings ^[1]. This ruling converts a policy dispute into a constitutional separation‑of‑powers question, placing the ultimate resolution in ongoing litigation and possible Supreme Court review, while creating immediate legal uncertainty for importers, exporters and trading partners ^[1].

2. Trump allies push a constitutional counterargument to keep tariffs alive

Legal teams supporting the tariffs have told justices that the measures are constitutional and within executive authority, arguing for broad presidential power to impose trade restrictions for national‑security, emergency, or foreign‑policy reasons; they pressed these arguments in filings and at the appellate level as litigation continued into late September 2025 ^[2]. This defense frames the debate as one of statutory interpretation and deference to executive branch judgment, and it signals an aggressive litigation strategy that could take the case to the Supreme Court if the appeals process continues, keeping the tariffs politically and legally contentious even after the appellate ruling ^[2].

3. WTO principles and a tectonic shift in U.S. tariff policy collide

Independent analyses and trade commentators describe the new U.S. measures as a departure from the WTO’s most‑favoured‑nation principle, since the tariffs apply broadly rather than through standard WTO exceptions or negotiated disciplines, raising questions about their compatibility with multilateral rules and increasing the risk of disputes and retaliation at the WTO ^[3]. The shift in U.S. tariff policy has prompted scrutiny not only in U.S. courts but also among trading partners and WTO members who may view broad, unilateral tariffs as inconsistent with post‑1945 trade norms, even as the U.S. seeks alternative justifications tied to national security and shifting global economic relationships ^[3].

4. China’s WTO status change adds a new layer of complexity

China’s decision in September 2025 to relinquish its developing‑country status for certain WTO benefits complicates how disputes over the U.S. tariffs might play out, because China’s altered status affects its rights and obligations under WTO agreements and could change the legal and diplomatic calculus for both Beijing and Washington in any complaints or countermeasures ^[4]. That change does not itself determine the domestic legality of U.S. tariffs under U.S. law, but it influences international dispute dynamics, potential retaliatory steps and the bargaining positions of WTO members when they assess whether U.S. measures violate multilateral commitments ^[4].

5. Economic critics highlight real‑world costs while stopping short of legal judgments

Business groups and economists emphasize that the tariffs risk economic harm to U.S. consumers and supply chains, citing potential price rises, disruptions for small businesses and broader dampening of trade‑dependent sectors; these critiques focus on policy efficacy and distributional effects rather than the narrow legal question, though they shape the political stakes that underlie litigation and legislative responses ^{[5] [6]}. Historical parallels—most notably comparisons to Smoot‑Hawley—are used to underline economic dangers, keeping pressure on Congress and courts to resolve whether the measures are justified legally and strategically ^{[7] [6]}.

6. Competing agendas: separation of powers versus executive flexibility

The debate centers on two contesting agendas: one emphasizing congressional primacy over tariffs and a strict separation of powers, and another stressing executive flexibility to act quickly on national security or foreign‑policy threats. The appellate ruling sided with the former by identifying statutory limits on presidential tariffs, while advocates argue the latter is essential in a fast‑changing global environment, framing judicial restraint as potentially hamstringing effective foreign‑policy tools ^{[1] [2]}. The outcome of ongoing litigation will shape whether future presidents can lawfully use similar authority absent new congressional authorization.

7. What to watch next: litigation, legislation and international pushback

The near‑term legal landscape will be decided by continued appeals, possible Supreme Court review and any congressional responses that either authorize or curtail executive tariff powers; meanwhile expect WTO complaints or diplomatic protests from trading partners as well as economic analyses tracking the tariffs’ effects ^{[1] [2] [3]}. The interplay of U.S. court rulings, legislative choices and international reactions will determine whether the tariffs ultimately remain in force, are limited by law, or prompt changes in both U.S. trade policy and the broader multilateral trading system ^{[4] [5]}.

8. Bottom line for the original question: “Are the tariffs illegal?”

As of the latest reporting and the September 2025 appeals decision, most of the tariffs were ruled unlawful under U.S. statute by a federal appellate court, but the ruling is subject to further appeal and the measures remained temporarily in effect pending that process; argument and litigation continue with strong counterclaims of executive authority and parallel international legal issues at the WTO ^{[1] [2] [3]}. The definitive answer will depend on the appellate and potentially Supreme Court outcomes and any congressional action, with international responses adding practical consequences regardless of final domestic legal rulings ^{[1] [4]}.