Austailia's offcial language is English, they don't tend to get themselves involved in wars (not in recent times anyways), and I can see Austrailia lasting for another century, which I don't forsee for the United States.
Canada would be too cold for my tastes and the United Kingdom is like Austrailia, but rains much more often, which sounds unpleasant.
So, in the event that your current country becomes unliveable, where do you plan to go?