I will end all legal traffic across the U.S.-Mexico border unless I get my stupid wall!

The President of the United States has literally no idea of what he is threatening. Closing the border would violate NAFTA, which means that Mexico would be able to use the treaty's dispute resolution procedure to force the U.S. to pay it for all of the losses it experiences from the border closing. Considering the amount of trade we have with Mexico, that bill would be enormous. And that charge would not count the equally enormous economic hit that U.S. businesses would take because of the border closing. If he is including closing air crossings as well, that will probably violate various open skies treaties (not just agreements with Mexico, it may also impact citizens of third countries' transit through or over the U.S. to get to and from Mexico).

And while this will be minor footnote compared to the economic destruction a true closing of all traffic with Mexico would bring, it would also mean thousands of MAGA-hat wearing fools will have to cancel their winter vacation in Cancun, etc.