National treatment is one rule. There are performance requirements that would preclude, say, value-added processing requirements for Canadian resources or the types of stimulus measures that the Canadian government might want to put into place. There are rules about expropriation, which has been interpreted too broadly. There's this jackpot article 1105 about treatment in accordance with international law.
So the fairness principle I wouldn't dispute. But I would argue that it's a feature of Canadian law in any event, and no U.S. investor can claim--