Zurich is also Engineering (any many staff in Zurich and London will be from other countries temporarily working there).

Which makes it even more difficult to limit access to Americans. Deepmind was originally a British company and has R & D in multiple countries to it will be even more awkward with them.

I have always thought the UK was too liberal in allowing foreign takeovers of key businesses. Arm and Deepmind are great examples of why.