All great empires eventually crumble, and through internal strife, not external pressure.
Bexit. The Scots voted to remain part of the UK in their independence referendum because we were in the EU. England voted leave, we couldn't care less what happens to Northern Ireland, and the Scots feel betrayed.
Australians received their kick in the teeth in 1975 which woke them up and they realised the Pacific nations were where it's at, and kinda thought a non political monarchy as head of state was better for them than an elected president in their referendum.
My own view is they are so appalled at the state of politics in the UK at the moment, I'm not surprised they want to cut their ties with us. I want to cut myself off from Westminster as well so of course I'm going to say something like that.
It's a fallacy we are a power on the world stage militarily. That belongs to the USA and China, but soft power was a strength we had which is now hugely diminished.
'Bring back control' was a misunderstood message during the rerendum. It failed to recognise our influence in the EU, especially our help to the eastern European members, and we were the gateway for the USA and other nations we had close ties with having a friendly voice for them in the most prosperous economic bloc in the world.
That influence we had has now been lost, and those countries we helped are now looking elsewhere because we are out of the club and out on our own.