[mandevil]

I mean, this is all true for a war today. But the economies were not intertwined as tightly in 1925, which is when these war plans were being drawn up. The US and Canada had had a pretty nasty border dispute (at least from the losing Canadian side) just twenty years earlier, well within the memory of most politicians running Canada. (I suspect that most Americans had forgotten about the Hays-Herbert Treaty of 1903 by 1925, but it would have been far more prominent in Canadian minds.) With the passage of another century I would be honestly shocked if such plans existed today on either side.