
The modern US hasn’t fought a war with someone right next door, who looks and talks like them. Not only would it be hard to hold captured cities, but I think many Canadian fighters would walk across that massive unsecured border and start fucking up US resources like electrical stations, water supplies, subway systems, internet backbones, government buildings, . It is super easy to buy guns and ammo in the US, bombs are not hard to make. We would have a fair amount of local support as well.
We Canadians could just walk around the US in public and you’ve never know it.
There would also be civilian targets. Those huge retirement towns filled with MAGA boomers in Florida - the ones where they drive golf carts around - those will burn to the ground.