Obviously the UK didn't vanish in a puff of smoke and nor will the US. America doesn't cease to exist it is just gradually ceasing to matter as I said.

I guess I didn't explain it clearly enough. For the US to stop mattering some other big guy will have to start mattering. I just don't see any country really taking on that mantle anytime soon. Maybe we are in a global decline and the only goal for the two big gorillas in the world is to outlast the other and only after that worry about what comes next.