Interesting post. Have you ever read about the bronze-age collapse (aka the invasion of the 'sea-peoples')?

It was the cause of the dark-age before the dark-age (yes, there have been several!).

Basically, around 1200BC civilisation fell apart and no-one knows why though scientists postulate that it was due to combination of several factors: war, famine, disease, population movements, and natural disasters- very similar to the factors you mention.

The key difference is, ofcourse, that all of these bad things occured around the same time, whereas it would appear that you believe any of these could wipe us out.

I would tend to agree with the former assertion, though I think the things you point out are potentially so much more severe (e.g. nuclear war vs old school war with swords AND/OR mass migration vs rise of the machines), that I fear you may be right.

I think I'll have a few extra drinks this weekend.