In a significant move, the U.S. Supreme Court delivered a ruling on Friday that deemed President Donald Trump’s tariffs on Canada and other nations to be illegal. However, this decision does not signify a cessation of Trump’s contentious trade policies. The ruling specifically targets tariffs enacted under emergency powers, including those related to fentanyl, while leaving many other tariffs intact. As a result, Trump retains the ability to impose additional tariffs, albeit under a different legal framework.
What the Ruling Entails
The Supreme Court’s decision arose from two lawsuits questioning Trump’s invocation of the International Emergency Economic Powers Act (IEEPA), a law from 1977 that grants the president authority to manage economic transactions during emergencies. The court found that Trump’s justification for imposing tariffs—citing fentanyl trafficking and trade deficits—did not align with the law’s intended purpose.
At the time of the ruling, Canada was facing a substantial 35 per cent tariff on goods associated with fentanyl, along with a 10 per cent tariff on energy and fertiliser products like potash. Notably, goods traded under the Canada-U.S.-Mexico Agreement (CUSMA) were exempt from these tariffs, a crucial point highlighted by Canadian Prime Minister Mark Carney, given that approximately 85 per cent of Canadian exports to the U.S. enjoy this exemption.
Remaining Tariffs and Future Actions
Despite the ruling, many tariffs remain in effect, particularly those established under Section 232 of the U.S. Trade Expansion Act. This legislation allows the president to impose tariffs on imports deemed a threat to national security. Currently, tariffs on steel, aluminium, and softwood lumber stand at 50 per cent, while automobiles and auto parts not compliant with CUSMA face a 25 per cent levy.

In response to the court’s decision, Trump announced plans to introduce a 10 per cent global tariff, stating that this would take effect immediately. This new tariff would be implemented through Section 122 of the U.S. Trade Act, which enables the president to address trade deficits, although it is limited in duration and percentage.
Unanswered Questions and Business Implications
One of the most pressing questions following the Supreme Court’s ruling concerns the potential for refunds to American businesses that have borne the financial brunt of the now-declared unlawful tariffs. Trump remarked on the lack of clarity regarding reimbursements, suggesting that litigation may continue for years to resolve the issue.
Several businesses, including major retailers like Costco, have initiated lawsuits to ensure they receive refunds for the tariffs collected during this period. The coalition We Pay the Tariffs, consisting of small U.S. businesses, has also launched a campaign to advocate for refunds, citing that tariff revenues during Trump’s tenure reached a staggering US$175 billion between March and October of last year.
Ongoing Trade Tensions
The implications of the Supreme Court ruling extend beyond immediate tariff changes, as experts caution that this decision could lead to increased uncertainty in global trade relations. Matthew Holmes, executive vice-president of the Canadian Chamber of Commerce, emphasised that this ruling merely opens a new chapter in an ongoing saga of tariffs and trade disputes.

Robert Glasgow, an international trade lawyer based in Toronto, noted that while businesses may benefit from reduced compliance costs associated with CUSMA exemptions, the overall landscape remains fraught with challenges.
Why it Matters
The Supreme Court’s ruling marks a crucial juncture in the ongoing trade wars instigated by the Trump administration. While it curtails certain powers, it simultaneously reaffirms the president’s ability to leverage other legal avenues to impose tariffs. This ruling not only affects trade dynamics between the U.S. and Canada but also sets a precedent for future trade policies and international relations, highlighting the intricate balance of power in economic governance. As businesses and governments navigate this evolving landscape, the potential for further conflict remains high, underscoring the complexity of global trade in the face of shifting political tides.