See, for all the big talk of annexing Canada, it’s a wide open border, Canadians look and sound mostly like Americans and overwhelmingly share cultural markers. It would be trivially easy to send snipers in vans to target random passerby in every American city. I am absolutely certain the US military did the math on how easily it could roll tanks into Ottawa and how many American civilians would be killed by unlimited guerilla warfare as a result of occupation.