Seriously - yes. Literally - ummm, no...ish.
Invasions during the American revolution and the War of 1812 and the Fenian raids following the US Civil War precipitated the unification of the Canadian colonies into a single country. Then, there was "War Plan Red" from the 1920's/30's.
So, whether it is meant to be a joke, or not, maybe you'll understand why we find it crass and boorish, rather than funny. But, if you find it funny, go ahead and yuk it up. Just be aware that pissing off Canada, Denmark/Greenland, Panama, the UK and Germany just plays into Chinese and Russian hands.