Feels like there's a very obvious answer that covers the majority of the answer and everything else is quibbling over the small remaining sliver. The UK and ot

Feels like there's a very obvious answer that covers the majority of the answer and everything else is quibbling over the small remaining sliver. The UK and other western countries were a global power because colonialism. Then WW2 happened and the US was mostly unscathed while also prioritizing long term growth through a stable democracy which led to high quality of life until the rest of the world caught up. We can talk about immigration, austerity, trade policy, etc. But these will only move the needle slightly. The overwhelming advantages that these countries experienced won't happen again until there's another major disruption.