Only sovereign because we allow you to be in order to humor you. Your entire system is thoroughly dependent on our own. You are joined at the hip-no the head-to us and you know it. We could break you up into the next 20 states of the Union if we liked. It would probably do you good and give you a chance to drive south for cheap liquor for those long cold winters without having to show a passport.
Are you serious? First off, "we"? Do you speak for the 300 million American citizens? Again, "me"? Who says I agree with everything my 30 million (yes the United States does outnumber Canada 10 to 1 in terms of population) countrymen decide or the way our government is run? If you notice, I never take jabs at American citizens as a whole, rather the policies and history of the government of the United States, which [may have at one time] reflected the wishes of the American citizenry. You make your premises clear... remember, if you try to slip your premises by people, you got them hooked... apply this to the government of the United States. Hardly anyone states their premises for anything anymore.
Secondly, the American military is at breaking point, it cannot subjugate Iraq, let alone Iran, how could it possibly afford to launch another offensive, and that on a first world country? Stop loss has been in place for what, three years now? Only way would be a draft, already being pushed in congress the last few years, but sofar rejected.
Thirdly, the American economy is having a nosedive while the Canadian dollar rises ever higher based on the primary and secondary industries that support it (the same industries America has exhausted/dismantled since their oil peak in 1970, but I digress...I would also like to add to the fact you may not want to harp on those of us that praise our falling populations).
Fourthly, the world at large would not condone this. Then again, they won't condone Iran, and most do not condone Iraq but that hasn't stopped anything. How many international laws do you think the gov't of the US would break? I suppose it wouldn't matter, since the WTO already declared the American tariffs on Canadian softwood lumber illegal, yet the US has yet to repay their debt.
Fifth, with what would you personally justify this? I don't want to attack your character but what would your country and countrymen gain from this? (Other than another half continent of resources to exploit full tilt, including the 3.5 mbpd of oil flowing...oh wait, you didn't know that Canada was the largest supplier of oil to the United States did you? Shhhh...don't tell anyone it's not Saudi Arabia, Mexico, Iraq, Iran or Venezuala, etc etc ad infinitum) How would the government of the United States convince it's citizenry that Canada needs to be annexed? And don't even think about watching Canadian Bacon starring John Candy(1995)!
Honestly though, since you bring this up, this is how I see it. The international bankers are trying to get the three largest member nations of North America (yes there are more...) to form a NAU because they can sense the impending importance of Canadian and Mexican resources for the largest oil user in the world (5% of the population, 25% of the oil), and obviously there is no sane way to justify taking it by force from these nations. Notwithstanding the fact that Mexico's superfield Canterall peaked two years ago and is facing massive drop off rate percentages. Since the media is not covering this development at all, it will be especially interesting to watch these secret conferences continue between the two presidents and the prime minister.