In the case of Bush, they were targeting a couple of people (fly-by-night unlicensed dealers) who sold guns that they knew were going directly to the Mexican drug gangs, and were selling large quantities of them to known Mexican gang members. None of the guns ever made it out of the country, and the guns (and the people) were apprehended as soon as the deal was closed.
Also, it wasn’t a set-up (F&F forced legitimate dealers to sell guns to people they knew were involved in crime and weren’t supposed to have them).
If Mexico did this to us Congress would declare War.