> Does the US have a strategic in that
It makes sense if you consider how Chinese companies moved factories to Mexico after the first round of tariffs. You have to treat every country consistently, all at once, or else loopholes emerge. That said, there's probably a smarter way to accomplish this, such as something like setting lower tariffs based on the first $x amount of trade deficit and increasing them by volume.
> It makes sense if you consider how Chinese companies moved factories to Mexico after the first round of tariffs.
Which benefits Mexican workers and by osmosis the US: the richer MX is, the more likely they'll become consumerist, and the US companies tend to sell a lot of consumerist goods.
Further, in the case of war, all those physical factories that are ostensibly owned by the Chinese could be nationalized by Mexico as they'd probably be more interested in being friendly with their immediate neighbour. Ditto for Canada: why is the US putting tariffs there?
Also: USMCA is only a few years old. There were already some Chinese-owned factories in Mexico at the time of its signing (which Trump at the time called "the best trade deal ever".) The Chinese factories didn't seem to have been a problem then.
> Which benefits Mexican workers and by osmosis the US: the richer MX is, the more likely they'll become consumerist, and the US companies tend to sell a lot of consumerist goods.
I was taking a specific example to illustrate why a general rule makes sense. It may be that your view of the specific example might be right, but that doesn't do anything to explain why the general rule isn't necessary. Suppose it's Vietnam instead of China. There's no similar type "osmosis" there. The particular country doesn't matter when you're trying to stop playing "whack-a-mole." At most, your argument might justify leaving very specific countries out while it still makes sense to keep the general rule for everyone else, and lo and behold Mexico wasn't on the list of new tariffs.
So the US is going to screw over every country on the planet because they might be used as loop hole? All to solve an imaginary problem?