Good point, although I was thinking more in terms of humanity as opposed to societies, but in a narrower term, yes, some societies will die out, pretty spectacularly, no doubt taking other societies with them, but eventually there will rise those who, as you say, lived within their means, and thus they will begin a new hegemony whilst the planet restocks itself, expanding into the vacuums left by their fallen comrades. Eventually as technology rebuilds and we claw our way back up, we will find ourselves back at the beginning.
Of course, such thinking beyond the inevitable collapse is a latticework of 'ifs' and 'maybes', but I will have to look up Jared Diamond. Thanks for the recommendation, I must have missed your earlier mentions.
There is one question though, one that I'm sure is plaguing all politicians minds right about now. What do we do to prevent such a collapse?
Certainly the first thing that must go is the realm of Political Correctness, as so long as society is cushioned by this comfort blanket, no hard decisions pertaining to the future of society can be made. Beyond that? Forced family planning? One child per family?
Or is it too late already?