I've been living in Montreal for 33 years and left 15 months ago, alone, with all my things shipped by boat to Peru. I have no plans to go back and now my family and friends all want to come see me, some already have. I just followed my feelings and now it makes even more sense. Montreal, is really a geographic position to control. Argonacon's observation about the probable event to hit such a city to align the consensus of the population to join the North American Union is just pure logic to me too. But I believe such an event would not spread far from Montreal and it would be more symbolic then extended real damages. Just enough to spread the fear that permits to then take more control. Would it work? Nothing so sure as there are lots of awaken good folks living there too!
Prepare for the worst but hope for the best is my motto.