What if the USA negotiates with the EU such that when the USA takes over Canada, every Canadian is given 1-month to declare either EU Citizenship or American citizenship. If a Canadian fails to declare, they're automatically made an EU citizen. The actual EU country they are citizens of would be up to how the EU wants to go about it.
This way all Canadians that don't want to be a part of the USA has the opportunity to move to the EU. I think this is a great strategy from the American perspective because in theory, it would likely rid Canada of the worst Canadians who'd take the EU citizenship. In this way, the USA only keeps the good Canadians so by bringing in Canada as a state, it isn't necessarily some mega liberal retarded state like California. This also might be a great way to sell the conquest to Canadians who may be quite happy with getting EU citizenship instead.
This seems like a win-win for everyone.
Canada's been a sovereign nation for 44 years. We don't know how independent Canada would hold up in a full war because they've only been involved in regional conflicts where NATO told them to go.
And before that Canada was just one of the UK's little commonwealth minions, only fighting as backup for the brits.