67th Tigers
Banned
Excuse me if I'm wrong, but didn't Canada tell Britain that if forced to chose between her and the US, Canada would side with America due to being its primary trading partner? Given the scenario, and if what I'm saying is true, Canada might decide to stay neutral, despite what London wants.
No, she is obliged to declare war when the King of Canada commands. Even if they could avoid it, I doubt anyone would have any illusions the US would respect it.