1) Two world wars in quick succession an empire killer 2) No planning outside of rebuild after world war 2 and losing the empire bit by bit. 3) No investment as a follow up to what got them the empire in the first place (innovation) 4) The brain drain to the US who bought their way to hegemony and success 5) Unionisation and political strife of the seventies followed by Thatcher and RayGun economics. A total fail. 6) Handing services to big business (Aus Anyone?) who systemically overcharge and provide a shit service. 7) Pulling out of Brexit with no plan and ironically having to have immigration prop up GDP. 8) Continual line of OxBridge inbreds from Eton, super privileged and not an ounce of thought for social conscience in any of them.
