Sorry for the late reply - that's cheating a bit, you know. The Eastern Roman Empire was Greek, not Italian. The Western Roman Empire benefited from Gothic vigor and fecundity and made quite a comeback in time, but it wasn't Latin anymore when it did so.
I do think it quite possible that if Europe does not see to its immigration policies it is likely to repeat history here. Unfortunately, if they attempt to incorporate countries with expanding, poor populations such as Turkey, whatever they manage to accomplish at the new border will be irrelevant.
The Greeks were even more "enervated" than the Romans. :)
The Western Roman Empire benefited from Gothic vigor and fecundity and made quite a comeback in time, but it wasn't Latin anymore when it did so.
You say this with a straight face...and tell me I'm cheating? :)
I do think it quite possible that if Europe does not see to its immigration policies it is likely to repeat history here.
That applies to all of the First World...including us.
Despite all I've said there's certainly SOMETHING to your argument. It may be that a stable social system has not yet been invented - it's either expand or die.