I agree with the lack of logic, as Trump yesterday announced wartime powers, using the pretense of being at war with gangs to justify the order.
That said, I don't see any invasion being based upon any real need, even from an economic level. In fact, such an act will be extremely counterproductive and will harm not only their general economy, but the bottom line of many of their top businesses. Not to mention that any project to extract Canadian resources that aren't already abundant in the US will take at least a half decade to even start producing, with profits only emerging two decades after any annexation at best.
And that presumes that any extraction is done quickly and smoothly. Frankly speaking, the issue is that to extract most things at scale, everything needs to be built up from the ground level, including roads.
That doesn't even start with the liklihood of constant protests and vandalism, including some crazies that try to shoot out tires and critical equipment.
Frankly, I'm fine that he's thinking this way. Things are too far gone and everybody has lost trust in the US at this point. Whether that was his intention from the beginning or if it's the idea he got after realizing that the backlash to his antics were magnitudes greater than what he expected no longer matters.
It will be years, if not decades, of hard work and consistancy before any major country trusts the US again for anything more than high-fructose corn syrup.
Trump can try to "put them back together" however he wants, but he'll be doing that without the rest of the world.