[skissane]

> A country is friendly until it isn’t

If the US can trust the UK with information on nuclear weapon designs and delivery systems, surely it can handle a few UK citizens working for SpaceX?

In the unlikely event that the UK and US had some falling out, the US government could always order SpaceX to lay off UK citizen employees.

[garmaine]

> If the US can trust the UK with information on nuclear weapon designs and delivery systems.

Bad example. The soviets got the bomb because of British spies in the Manhattan project. After that, there was very little collaboration to this day.

[skissane]

What about the 1958 Mutual Defence Agreement? That led to sharing of nuclear weapons design information, over a decade after the Manhattan project.

https://en.m.wikipedia.org/wiki/1958_US–UK_Mutual_Defence_Ag...

[garmaine]

Read the details; it wasn’t free exchange of information. It was basically a way for the US to allow sales of some nuclear plants and material, and sharing of design work only when it overlapped significantly with what the UK already did.

[skissane]

Which details? Wikipedia says:

> The Americans disclosed the details of nine of their nuclear weapon designs: the Mark 7, Mark 15/39, Mark 19, Mark 25, Mark 27, Mark 28, Mark 31, Mark 33 and Mark 34. In return, the British provided the details of seven of theirs, including Green Grass; Pennant, the boosted device which had been detonated in the Grapple Z test on 22 August; Flagpole, the two-stage device scheduled for 2 September; Burgee, scheduled for 23 September; and the three-stage Halliard 3. The Americans were impressed with the British designs, particularly with Halliard 1, the heavier version of Halliard 3. Cook therefore changed the Grapple Z programme to fire Halliard 1 instead of Halliard 3.[85] Macmillan noted in his diary, with satisfaction that:

>> in some respects we are as far, and even further, advanced in the art than our American friends. They thought interchange of information would be all give. They are keen that we should complete our series, especially the last megaton, the character of which is novel and of deep interest to them.

> An early benefit of the agreement was to allow the UK to "Anglicise" the W28 nuclear warhead as the Red Snow warhead for the Blue Steel missile.[87] The British designers were impressed by the W28, which was not only lighter than the British Green Grass warhead used in Yellow Sun, but remarkably more economical in its use of expensive fissile material.

Wikipedia doesn’t appear to support your version of events. (Of course, Wikipedia is sometimes wrong; but if you think it is wrong, which of the above claims it makes is wrong specifically?)

[rbanffy]

And what will you do with their knowledge?

[skissane]

It seems rather silly to me to worry about the knowledge of a few UK citizen SpaceX engineers, in the event of a hypothetical US-UK breakup, considering how much information the US and the UK already share in the fields of nuclear weapons and SIGINT. Surely knowledge about the later two is a much bigger concern than the first? Yet, if they are willing to risk the later, why not risk the former as well?

Besides that, the risk of a US-UK breakup has always appeared to be low, and Brexit arguably makes it even less likely.