(Can’t comment on US – though does anyone really assert that a common USN/USAF F-4 was a bad idea?). All UK cancellations were caused by the role changing (high altitude supersonic bomber Avro 730), becoming unaffordable in competition with other calls for money and men (supersonic V/STOL P.1154 and its HS681 bowser), or…doubt by the buyer that it could be built on time/spec/budget (Thin-Wing Javelin). This one makes the thrust of the thread moot: if Gloster couldn’t make thick-wing Javelin work by 1956, after 9 years’ privilege, it’s pointless to surmise any later G.A. might have been “Great”.

The only UK deletion that we should cry for was Filton-built Theseus/L-849, whose application to 1947 Cabinet for a ration of $ was declined because the country was skint. That, and only that, would have been better than what we actually operated.