Nobody is really explaining to me why it's an invalid comparison, though.
Well, Netum did come up with a fair point:
In 1900, Russia was a great power, had a developing industrial base, many natural resources, was plagued with instability and had a population of 128m
In 1900, Mexico was a minor backwater, had no development, many natural resources, was plagued with instability, and had a population of 13.6m
I´d argue that today they aren´t that different, but back then they were.
And now, if we consider the cold war we can see that Russia truly has an awesome potential. It managed quite a lot despite a paranoid crazy leader, stupid economic policies and a horrific invasion.
I´m thinking about population here. Of course one shouldn´t underestimate Mexico´s potential either. (Resources, space and also industrializing).