The dubious legality of Trump's tariffs

If you were thinking, hold on, Trump's tariffs on Canada can't possibly be legal, then yes, that's quite right, but probably irrelevant. An expert on international trade law lays it all out.

Firstly, yes, we have a free trade deal with the USA. Known to us as CUSMA (Canada-United States-Mexico Agreement) and to the Yanks as USCMA (and probably to the Mexicans as MUSCA, which is the easiest one to say), President Trump signed it himself in 2018 (and the final version in 2020), and it replaced the original 1994 NAFTA agreement. And yes, Trump's tariffs are a clear violation of CUSMA, which explicitly states that member countries cannot simply increase tariffs unilaterally.

And yes, there is a dispute mechanism involving a legal panel. Canada would probably win any such dispute, even if the US uses various national security defences (Trump is mainly using the International Emergency Economic Powers Act - IEEPA - to justify his tariff impositions). But if he is willing to directly contravene the wording of the Agreement, it is unlikely that he will care much about a ruling by some dispute panel.

There is also the World Trade Organization (WTO), of which the US is still technically a member, although Trump has repeatedly threatened to withdraw from it. Canada would probably win a case before the WTO too, but Trump is unlikely to abide by any decision (and could just pull out of the organization if it suited him). The WTO has no real teeth to enforce its rulings.

Of the two, the CUSMA route is probably the best bet, although, as has been said, Trump does not appear to care about the agreement, or about legalities in general. He would just steamroller through regardless. Although such a case could be brought relatively quickly (meaning within a year!), the US could stall the process of picking a panel for quite some time, and the majority on the panel is decided by (quite literally) a coin toss, which is a bit bizarre.

There is also the possibility that US domestic lawyers could challenge his use of the IEEPA, which was never intended to be used for tariffs against a friendly nation. The Government of Canada could be involved as an amicus (intervenor) in such a case.

All of these legal remedies, however, take time, and in the meantime both Canada and Mexico (and the USA!) are suffering economically. And there is no guarantee that Trump would abide by any legal decision he doesn't like; he is past the point of concern with legal niceties. It may still be worthwhile pursuing from an international optics point of view, but again, Trump does really not care about optics, and the rest of the world already knows he is in the wrong.