Pandemics cause state collapse and goes nuclear

There are several periods when we get discontinuities, when we get collapses in social development scores. You can see several very clear examples on this graph. When we look back at the history of what happens when we get these great collapses in social development, every time we see the same five forces involved: Mass migrations that the societies of the day cannot cope with. This is always in the mix. The mass migrations often lead to huge epidemic diseases, as previously separate disease pools get merged. Epidemic diseases regularly killing half the population, it would seem, tend to lead to state failure. Governments cannot cope with catastrophe on this scale. The collapse of the governments tends to lead to breakdown in long-distance trade. Famines ensue, many, many more people die. And then, always there in the mix in some way, although it varies in every case, is climate change. It always plays into this. Now, I'm sure you don't need me to tell you these are forces that plenty of people are talking about as threats we are facing in the early 21st century. It seems to me perfectly possible that the 21st century is going to see another collapse of the kind we have seen so many times in the past. So in some ways it's possible the 21st century might be a rerun of what has happened many times before—but with one big difference: We now have nuclear weapons, which ancient people didn't have. The Romans would have loved nuclear weapons. Luckily, they didn't have them. I think if we do stumble into a collapse on the scale that I'm talking about here, we should seriously expect there is a possibility of these being used. It's quite possible that the 21st century will see a disaster that dwarfs anything we have seen earlier.