In the cumulative effect of the events describe in my opening post, the danger is that 

(a) Mexico elects a populist Government in the upcoming election (around June, I believe) & begins matching Trump's posturing bravado for domestic political purposes, &

(b) confusion reigns regarding NAFTA in the run-up to the US midterm elections as pro & anti-NAFTA elements in both the GOP & Democratic Parties harden their positions.

NAFTA in its current form would remain in force but politics, markets & forward planning by Governments, industries, corporations, etc. would be impeded for a protracted period.

Hopefully, saner heads within the Trump Administration & the GOP will prevail on Trump not actually to invoke Article 2205 (in light of the negative effect on the US that would have, if for no other reason).