Don't count out China. The CCP has a lot riding on the Belt and Road Initiative. They've put a lot of work into putting together the BRICS network. They may not be so keen on the US destroying their plans.
Discussion
I'm not counting them out, but if they do anything kinetic I suspect it'll be Taiwan, while the US is embroiled in Ukraine and Iran and I'm not even sure they'll do that, given how well they're doing for themselves through non aggressive diplomacy.
Taiwan is tough. The Chinese will have trouble bringing ships over outside of October and April. The straights get turbulent. They may decide that shipping weapons to Iran is a better use of their time right now.