"Most big science publishers are based in Europe, but a huge percentage of their revenue comes from the U.S. If the Trump administration demanded that these publishers block unapproved publications from the U.S., would they stand and fight?"
https://www.thetransmitter.org/policy/science-must-step-away-from-nationally-managed-infrastructure/
Of course they wouldn't! We've seen them roll over for much less, e.g.:
https://bjoern.brembs.net/2014/04/resigning-from-frontiers/
That was 11 years ago and things have changed for the worse since then.