I don't understand why the US government would not allow it. Currently, with no changes to any policy Air Canada can fly US passengers anywhere in the world except the US using mostly Canadian crews so what would the US government be protecting against?
As is done in other industries, a US domestic operation of Air Canada would need to be run by a US subsidiary (often they are named something like ACE
Holdings USA) and would operate US domestic flights as Air Canada using US crews, US maintenance, US everything else, and would need to pay US taxes, but ACE
Holdings would own it and this corporation can be bought on the stock exchange by US citizens, Canadian citizens, and people around the world. The US operation of Air Canada would benefit Americans as much as any other business in the US would except for the few top jobs of ACE
Holdings of which there are only a few. If you look at Air Canada the CEO is from the US, and the old CEO of AA
was a Canadian so when you think about it does it really make any difference?
As long as airlines are forced to have local subsidiaries run domestic operations like other industries do I don't think anyone looses because these local subsidiaries end up being run under the same rules, tax laws, and playing field as any other local company.