I heard an interesting theory that the stupid tariffs on Canada are intended to destroy their economy and force them to surrender their sovereignty to the US. He doesn't care if his threats trigger nationalist backlash because he thinks Canada is so dependent on the US that they can't resist.
I'm not sure he actually has a plan, but if there is a plan I could see it as a play for conquest.
That would be absolutely mentally deranged reasoning but given other shit hes done, like cancelling the CHIPS act, i would not at all be suprised if this was how he thought/planned