You would need the FTC to intervene to stop the acquisition. And currently there is a massive lobbying push by US technology companies to replace Lina Khan with someone who is more merger friendly.
China is busy replacing imported CPUs with domestically produced ones on a massive scale. Qualcomm's China business is at risk of collapse anyway. I don't think the Chinese will be interested nor able to buy Intel and AMD x86 chips for much longer either. My guess is that Qualcomm can placate them by promising to leave Zhaoxin alone (legally binding of course).
UK CMA folded extremely quickly after FTC lost their lawsuit. Microsoft had already communicated that they would withdraw Activision Blizzard products from the UK in case the deal were continued to be blocked.
The EU is a bit of a question mark, but blocking the FTC approved merger of two US companies could be seen as too costly politically.
https://www.bloomberg.com/news/articles/2024-09-06/kamala-ha... (non-paywall archive link: https://archive.md/PhHhU )