I wouldn't doubt that there are sleeper cells, but they would be flea bites compared to the armed forces of the United States. The Mexican Air Forces - if they resisted - would cease to exist in the first 48 hours.
I am sure that the average Mexican would far prefer to be under American leadership after the corrupt nightmare that has always been the Mexican political system.
Mexicans are proud people and would not stand for Gringos dominating them. They still remember the Mexican War and all the territory the US took from them.
Now they are practicing “Reconquista”.
Sleeper Cells in the US would raise hell and in some cases paralyze whole cities. Don’t underestimate an enemy. You should know that.
Nation building in Mexico would not be a good thing or work out. We have our own disasters to deal with.
Welcome Home! I was in the 101st Abn. in I Corps and we took over when the Marines pulled out of I Corps.