With all due respect Mr Rozenthal, you know better than that.

Nations do not have friends, they have interests. Where those interests find commonality and mutual benefit, deals can be made.

Considering just Canada and Mexico, please make the case for each nation. 

What does Canada need Mexico for? What does Mexico need Canada for?

You speak of advantages that could be lost - what are they? 

A few months back, the CBC interviewed a family owner of Hammond Manufacturing, a long time Ontario manufacturer of electrical equipment. They were in the midst of shifting ALL manufacturing to Mexico. Cheaper, and improving quality.

I recently worked on a project where Hammond components were specified.

Congratulations. For Mexico. But for Canada? What do we get in the bargain, except for long term erosion of living standards?