According to your experience, sagacity and knowledge, what reasons or causes would be a threat to our Western civilisation?

History is the study of the past, and several civilisations have preceded ours.  From what we’ve learned, sometimes in detail, can it be possible to prevent a similar fate like the ones of our ancestors?  In my opinion, the main difference with the past is that Western civilisation doesn’t depend on one place mainly (Europe, USA, Australia, etc. and not Rome or Aachen, Paris, London or Washington).

Western civilisation has spread worldwide. Is it enough ?