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That’s just a guess from me, but since the UK has a domestic nuclear weapons programme, it would make a lot of sense to them to develop their own bombs and equip their own aircraft for dropping them.
A different part of the UK’s nuclear deterrent is awfully US dependent, though, they chose US made Trident ballistic missiles as carrier system for their submarine launched strategic warheads.
If German politicians behaved like adult human beings, and did, as they are supposed to, work for the good of the entire country, then, this would work. The problem is that they don’t, most of the time.