Well look at the plummeting of our aircraft industry for a start, we still have some good designs but now it is all collaberations.
What happened to the industry which gave us the Harrier, TSR2, Lightning, previously Spitfire, Hurricane & Lancaster.
Not to mention 2 of the best jet heavy bombers.
Just a large share in Eurofighter left!
And don't start any of us off on Concorde!