NAFTA is not a treaty, it is a trade agreement and that means it is regulated by the US Congress and not international law.
It has provisions in it that appear treaty-like but they are not legally subject to international law, they are subject to Congressional regulation.
You can’t talk about TPP yet because it’s not public. When it’s public, then that is the time to chime in.
I don't follow. If the U.S. breaches NAFTA, then what is Canada's remedy after adjudication? You would seem to suggest an equal and opposite breach, rather than enforcement/mandamus that a treaty might provide. Do I understand correctly? Retaliation is the example that Sen. Cruz gave yesterday.
Did anyone other than the speaker of the house, the senate majority leader and the President of the United States sign the Nafta agreement?