[arethuza]

"I dont get why people keep thinking the UK has a special relationship with the US anymore"

I can't say I am a fan of the "special relationship" (I'm in the UK) - but worth noting that I don't think the US sells Trident missile technology to anyone else? UK warhead designs are probably US based as well although we do manufacture them ourselves.

[Crito]

My understanding is that the US was not particularly open with nuclear technology initially. The UK developed fission bombs and designed thermonuclear bombs more or less independently, demonstrating that they had done that to the Americans, and the Americans then became more open to cooperation.

The US even allowed the UK to test some of their bombs on American soil, in Nevada. (The UK also tested nuclear bombs in Australia. They don't have much wide-open desert of their own).