I think the quickest and most long-lasting thing is “Make Mexico the wall”.
Not “Make Mexico pay for the wall”.
Not “Make Mexico build the wall”
Make Mexico BE the wall. Essentially, colonize the place, give the white elites so much money they conform to our needs, build a real wall on the Guatemala-Mexico border. Turn Mexico into our Croatia, in other words.
That would have worked had we done it in 1848.
Ok, ok..... I figured it out.
The State Department will give Mexico $10 billion.
Mexico will then pay the Corps of Engineers wall contractors based on monthly invoice approval by the Corps of Engineers. This arrangement will go forward as long as the money lasts.
This arrangement was negotiated by Trump and the incoming Mexican President as a part or perhaps as aa secret addendum to the recent trade negotiations. The Mexican President agreed because Trump made him an offer he dared not refuse