Occidental civilization cultivates the myth that it is indefinitely progressing, but - in face of the increasing paranoia, avarice, corruption & disorientation of its subjects – it is definitely declining.
All civilizations do eventually disappear, be it through inner corruption, outer pressure or suicide. Corruption is foremost powered by ambition, envy & greed and manifests in the Occident and its dependencies as turbulent changes of personal & collective parameters, intoxication & consumption frenzies, sexual abbreviations, media saturations, political opportunism, escape cults and so on - as a matter of fact, most aspects of present Occidental civilizations can be seen as manifestations of weakness, disorientation and decay. And it seems to have suicidal tendencies as well, considering the zeal with which its citizens attack, rape, plunder & poison the organism that bears and feeds them.
Occidental civilisation developed in a linear time/space which reaches inevitable (at least since the beginning of Dualism) its own end. And then there is going to be an end of all beginnings and of all the abstructs that originate from this R/P relationship – since it is the relationship which determines a formation.
There is little known about the causes of the disappearances of other civilizations, probably due to the collective amnesia that usually comes in the wake of a catastrophe. However, the reasons of the decline of the Occident are largely known, dynamics and details are well researched and recorded – yet, be it due to lack of common sense, simple stupidity or genetic fuck-up, Sapiens carries on with business as usual attitude.
Nevertheless it would be unjust to blame Sapiens, after all he is but an epitome of Dualism and thus subject to a polarisation dynamic that increases (according to the dual-linear relativity of Dualism) at an exponential rate.