I'm here to educate people StR, especially those who are 'so...

I'm here to educate people StR, especially those who are 'so blind they will not see'.

but if you are still interested you might like to have read of, say, Arnold Toynbee :- famous for his turn of phrase :- "Civilizations die from suicide, not by murder." It's only a dozen books to get through, an easy read for a scholar like yourself

The list of precursors are many, but do not need all to be satisfied for the collapse.