Europe is a very large market and ignoring it does not make much sense, countries buy high tech components and armaments and they are aligned in terms of export controls. Europeans have a lot of high tech products that are valued globally.

No.

But people will remember that no and realise that they need to arm themselves because allies can’t be relied. Next you will have nuclear arms race everywhere, particularly Europe and Asia.

Is it what US wanted/don’t care? If not then it is the leverage

Europe could remind Trump that he's going to need our alliance if he plans to confront China. It looks less and less like he does though.