There is more, Claudia. Take a look at this http://www.edmontonjournal.com/business/Gary+Lamphier+often+experts+leave+their+footprint+with+feet+clay/2288739/story.html especially the part about the US coal industry.

Frankly, I am in favour of no more oil being sold to the US. Canada is the largest supplier to the US, and frankly it makes more sense to ship the oil to Asia. As for the chest thumping about the US defending Canada militarily, I know this: each commander, regardless of military branch, has a budget. When the budget is spent, nothing happens. So, given the US is flat broke, where is the money going to come from to fund the military?
Will China accept more debt? I don’t think so.