Yeah, I know Stant and you didn't make him angry or insult him. He's not exactly the thin skinned son of a bitch some think of him as. Oh, but he can be a son of a bitch. 
As for Mexico's problems, I won't argue that countries don't influence one another, but there is truth in doing the job yourself is the best way. No one can force another country to do everything it wants and, in any case, there is blame at the homestead as well. So, the best thing to do is fix what you can. Arizona was getting Mexican crime (they were Mexican citizens, so it is Mexican crime) in their city streets. Do they tell Mexico to fix the problem? Nope, they go out and start hauling in illegal immigrants. It may or may not be perfect, but it's what they can do and they're doing it.
Utopia? I have high hopes and low expectations for humanity. In either case, I'm not going to be a part of it.
Countries lasting forever? Stant didn't said anything about that. Not sure if I can help you there.
As for economics, it is what it is. If you look back to when America was not a super-power, someone else was doing something exactly like they are and their neighboring countries felt exactly the same way. I even own a Gehendra rifle which is the product of such a system long before America was in the top 10 most powerful countries.
Oh, and the Aztec weren't the victims of corruption. They were the victims of guys with guns.
