This week’s ah hoc, slapdash, ‘ready, fire, aim’ farce illustrates is that Trump is now conversant with Article 2205 of NAFTA which allows any country to withdraw provided it has given 6 months prior notice to the other 2. He sees how well the leverage it affords fits his negotiating style. 

Also, Trump may soon make an Executive Order directing that a 6 month review (specifying changes the US must insist on) begin concerning all US trade agreements, including NAFTA and under WTO,

Thus, if Trump makes the 6 month review order, then Canada and Mexico must seek clarification at the highest level of US goals and, if adequate assurances aren’t given that the review will not result in new demands in 6 months and that an Article 2205 will not be made while NAFTA negotiations continue, declare that they are no longer prepared to commence NAFTA negotiations unless and until the US commits to negotiate without threats and on a stable, reasonable and equitable basis.