The UN? You mean the cowardly, blue hats, that are known for raping, robbing, molesting and pillaging everywhere they go? The only reason they go anywhere is because the US pays for everything. They are beyond useless.
Both the Russian and Chinese armies are nothing more than conscript armies that, while large, are poorly trained and would have to cross oceans to get here.
As for the narco-gangs, yes they are violent. Against unarmed mules and immigrants. Let them come up against a group of guys that have a clue and they aren’t going to hold a line anymore than a squad of hipsters in LA.
The biggest reason we have issues on the border or elsewhere is, because the American military is restrained. Do you or anyone else think that the issues we have on the Southern border would last, if we were shooting people on sight?
I understand that what you write about is a consideration, but let’s not underestimate the abilities of the people of the USA, especially in a scenario like this.
There is nothing more devastating than fire from a concealed .306 shooter from which there is no relief, and no answer.
The Narcos are getting trained by military vets.
They are getting better.