I think they'll go for economic collapse with famine/disease killing many and the fomenting of race wars wiping out more of the excess in the US and Europe. G. Edward Griffin's Pessimistic Scenario in his book The Creature from Jekyll Island has a similar scenario.
If you're into financial/monetary stuff, I can highly recommend that work. It describes how the money masters rule the world via their network of central banks by manipulating their debt money system. Since it was written, we've had QE and bank bailouts galore. You can read and/or download it for free here:
https://archive.org/details/Creature....EdwardGriffin and here's hundreds of user reviews
https://www.amazon.com/Creature-Jeky.../dp/0912986212
On a separate note, his book/video A World Without Cancer
https://www.youtube.com/watch?v=QeYMduufa-E he makes a compelling case for why everyone can easily avoid getting the Big C.