It should be remembered that, despite our holding a seat on the UN Security Council, as well as at various global economic conferences, Britain has been a 2nd-level (perhaps even 3rd-level) nation for several decades.  Even before the 2nd World War, we were losing our status, which we sort of regained as a result of our standing alone against Hitler for a year or so.  It was a temporary reprieve, and no subsequent Government has really managed to reverse it - although some ideas, such as the NHS, have proven to be world-leaders in their fields.