Senior administration officials told reporters the move is meant to punish Canada for what the U.S. says is discrimination against American industries.
Specifically, the U.S. claims Canada has treated makers of motor vehicles, alcohol, and dairy products unfairly. One official said, "By doing this, President Trump is leveling the playing field for crucial American exports: motor vehicles, alcohol, and dairy." Another added, "Canada has to be held accountable for this continued discrimination."
The tariffs do not take effect right away. There is a 30-day window before they kick in, which gives both sides a little time to talk or adjust.
What makes this move unusual is the legal tool Trump used. The tariffs are based on Section 338 of U.S. trade law. If that name does not ring a bell, there is a reason.
Get the market news that matters in a five-minute read with Market Briefs, our free daily newsletter
According to lawyers John Veroneau and Catherine Gibson, who discussed the law in a 2016 article, the government last invoked Section 338 in 1949, and there exists no subsequent public record of its use. Under this statute, the president may levy additional duties of up to half the value on imports from any nation that unfairly restricts U.S. commerce.
Officials at Canada's diplomatic mission in the U.S. capital did not respond promptly to a query regarding the new trade actions.
The revival of this obscure law signals a dramatic escalation in U.S.-Canada trade relations, which have been strained since Trump's first term. Section 338 was originally enacted in 1930 as part of the Smoot-Hawley Tariff Act, giving the executive broad authority to retaliate against foreign discrimination. It had fallen into disuse as the U.S. shifted toward dispute resolution via the World Trade Organization and the USMCA.
Section 338's revival marks a sharp departure from modern trade policy. The Smoot-Hawley Tariff Act is historically notorious for worsening the Great Depression, and using a provision from that era signals a willingness to bypass established WTO and USMCA dispute mechanisms.
The use of Section 338 represents a significant departure from the post-World War II trade order, which emphasized multilateral dispute resolution. The Smoot-Hawley Tariff Act, of which Section 338 is a part, is widely blamed for exacerbating the Great Depression by triggering retaliatory tariffs worldwide. Modern trade agreements like USMCA and WTO rules were designed to prevent such unilateral actions, but Trump's invocation of this obscure provision suggests a willingness to bypass these frameworks. Additionally, the 30-day delay provides a window for negotiations, though the separate consideration of tariffs linked to Canadian wildfire pollution adds another layer of complexity to bilateral relations.
Separately, Trump has asked for options on additional tariffs related to Canadian wildfires that have caused air pollution in the U.S. The administration says the current 50% tariffs are not connected to that issue, but Trump posted on Truth Social that the costs from the wildfires "must of necessity be added to the TARIFFS Canada is currently paying." One senior official confirmed that Trump "has asked for options on that."
Join Market Briefs, our free daily newsletter, for a quick daily rundown of the markets
