In a significant ruling on Friday, the U.S. Supreme Court declared that President Donald Trump’s tariffs on Canada and various other nations were unlawful. However, this decision does not signify an end to the ongoing trade conflicts initiated by the Trump administration. The court’s verdict mainly pertains to tariffs imposed under emergency powers, particularly the controversial “reciprocal” tariffs and additional duties related to fentanyl imports from Canada. While this ruling curtails Trump’s ability to unilaterally impose new tariffs, it does not dismantle all existing trade barriers.
Overview of the Ruling
The Supreme Court’s decision was rooted in two lawsuits that contested Trump’s invocation of the International Emergency Economic Powers Act (IEEPA) of 1977. This legislation permits the president to regulate economic transactions during national emergencies. Trump justified his tariff actions by citing emergencies related to fentanyl trafficking and trade deficits with numerous countries.
At the time of the ruling, Canada faced a staggering 35 per cent tariff on fentanyl-related products, alongside a 10 per cent tariff on energy and fertiliser goods like potash. However, under the Canada-U.S.-Mexico Agreement (CUSMA), many Canadian exports enjoyed tariff exemptions, accounting for approximately 85 per cent of trade.
Existing Tariffs Remain Unaffected
Despite the Supreme Court’s ruling, several tariffs targeting specific sectors remain firmly in place. These tariffs were imposed under Section 232 of the U.S. Trade Expansion Act, which allows the president to take action against foreign imports deemed a threat to national security. This includes hefty tariffs on steel, aluminium, and automobiles, which are currently set at 50 per cent and 25 per cent, respectively.

Trump has indicated that he plans to utilise Section 122 of the U.S. Trade Act to impose a new global tariff of 10 per cent, extending beyond the tariffs already in effect. This executive action is designed to address trade deficits but is limited to a maximum of 15 per cent and only for a duration of 150 days unless extended by Congress.
Future Implications for U.S.-Canada Trade Relations
The implications of the Supreme Court’s decision are multifaceted. While it restricts Trump’s immediate tariff powers, the potential for future tariffs remains substantial. Observers have noted that the ruling merely opens a new chapter in the ongoing saga of trade disputes. Matthew Holmes, Executive Vice-President at the Canadian Chamber of Commerce, remarked, “This really guarantees more uncertainty and likely more tariffs down the road, both globally speaking but possibly for Canada as well.”
Legal experts are also raising concerns about potential refunds for American businesses that have been burdened by the now-illegal tariffs. President Trump has stated that the IEEPA tariffs have generated over $164.7 billion in revenue for the U.S. government, raising questions about whether this money will be returned to businesses that paid the excessive tariffs.
The Path Forward for Businesses and Trade
As American businesses await clarity on refunds, many, including large corporations like Costco, are pursuing legal action to recover their losses. The coalition “We Pay the Tariffs” has initiated a campaign to push for an efficient refund process, arguing that small businesses cannot afford prolonged bureaucratic delays.

Robert Glasgow, an international trade lawyer from Toronto, noted that while the loss of preferential access under CUSMA could complicate trade, the reduction in compliance costs tied to obtaining zero-per-cent tariff rates could benefit domestic entities in the long run.
Why it Matters
The Supreme Court’s ruling shines a light on the precarious nature of global trade relations under the Trump administration. While the decision restricts certain tariff powers, it does not eliminate the potential for future impositions or trade conflicts. This ongoing uncertainty could have lasting repercussions for businesses and economies reliant on stable trade agreements, particularly between the U.S. and Canada. As the landscape of international trade continues to evolve, stakeholders must remain vigilant and prepared for further developments in this turbulent arena.