Re: Jet Engine
The UK literally sold the USSR the technology for the early MIG engine.
Yeah, right, because the USSR could never have mastered that technology on its own. The same sort of thinking that lead the Americans to renege on all their commitments regarding nuclear technology with the UK - because the British couldn't possibly build a bomb themselves without access to American designs. Oops.
Human IQ is pretty much the same everywhere. You can't contain an invention once other people have seen it in action because they will always be able to infer most of the operational details immediately and rapidly resolve the rest experimentally if they have enough money and resources.
Licensing jet engine designs to the USSR made a profit an ensured that we had a damn good idea what the operational capabilities of those engines were. Refusing to do so would just have resulted in the USSR ending up with indigenous designs whose capabilities were more opaque.
The F35 paranoia is equally farcical - unless you seriously believe that the guys at Lockheed have genetically bigger brains than those at Mikoyan or Sukhoi. American military supremacy is based on money, and if the Russians can't match the F35 or a nuclear Super Carrier it is because they don't have the budget, not because they don't understand the engineering.