And magically... they don't get attacked. Funny how that works...
[1] http://www.fallen.io/ww2/ (Skip to the 14 minute mark if you're impatient)
Interestingly, this convention is signed and ratified basically by the whole world, but not by the US.
[0] https://thebarentsobserver.com/en/arctic/2019/04/russia-scor...
[1] https://en.wikipedia.org/wiki/United_Nations_Convention_on_t...
During WWII, do you think appeasement would have worked?
The reason many evil countries aren't bombing the US and Canada is because they know they would be obliterated by the US military due to past campaigns.
Protected from what? From the White Walkers?
Who is there to attack Canada (besides the US itself)? The Great Britain is trying to return the lost colony? France is thinking about taking over the Quebec?
To give you an couple examples in the current real world, imagine if South Korea or Taiwan didn't have such good relations with America in the post-WW2 peace. It is not that far fetched to think that there could be a single communist Korea, Taiwan could have been swallowed up by mainland China.
I don't think that Canada in your alternative universe would've been worse off than Finland in this one. Finland's neutrality kept it safe ever since the WW2.
When push comes to shove, neutral countries eventually need to pick sides or they will be taken over.
You cannot seriously assert that if Germany beats the UK and Russia, they will decide to simply leave Switzerland alone?
https://en.wikipedia.org/wiki/Operation_Tannenbaum#Nazi_atti...
And magically... a lot of countries that aren't Canada still get attacked. Funny how that works.
Want to scare the world and become known? Canada probably isn't the place to do so, the US is way bigger, has more news outlets, and enough targets that you can probably hit at least one of them.
Want to show the world how cruel you can be, and inspire revenge? Attack Canada out of the blue- the stereotype of Canadians being super chill and apologizing is international, and attacking them will get everyone and their dog angry at you.
Want to do a lot of damage? US.
Want to show that your country is capable of going toe-to-toe with a first-world country? The USA is your best bet.
As alluded to by other commenters, Canada is also protected because its physical barriers touch the United States', and anything major that affects Canada will also affect the US, too.