Trump tries to betray Canadians here. When you make negotiations and then at the last second try to worsen the terms, you are not acting in good faith. This is a consistent theme with Trump: he wants to take advantage of you. This is a de-facto mafia system. The "art of the deal" is the mafia way. You can see this with Iran too - Trump negotiates, then attacks. Then fake-negotiates, attacks again (and loses anyway). The guy is a problem for the whole world.

That should read, Trump betrays Americans. The reality is that he is destroying American credibility on the international stage, which is going to have long term effects on their ability to make agreements with other countries in the future. Standing alone is not in the interest of any nation.

As for betraying Canadians, Trump is not responsible for representing Canadian interests. I wouldn't want him to either. (Speaking as a Canadian.)

Trump attacked iran in the middle of negotiations. It's probably a pattern from the salesmen book he didn't even write.