The ways Trump has outlined Mexico paying for the wall doesn't require Mexico's permission.
That's really a moot point (permission)
Just how is Mexico going to be forced to pay for the wall?
Add a surcharge to money transfers to Mexico ? ...A lot of that money is earned by americans or legally here mexicans...so a percent of that wall is being paid for by Americans...
Take the money out of their foreign aid package...That's american taxpayer money...
Send the Mexican government an invoice? ...good luck with that
I'm all for Mexico paying for it, I just don't know of a way to make them pay for it..?