If this administration actually becomes convinced that some imminent training run is likely to kill everyone, why wouldn't they act?
The key is winning the debate that ASI is species-cide by default.
We have to win it either way, because the 2028 US elections have little or nothing to do with what Xi does.
(It's clear now that they can do plenty of harm before they are made public.)
But it's a proof point that regulation is possible, even over the objections of the companies.
What news have you seen that made it seem less like a retaliation?