@joywyx0 , generally agreeing with my colleagues @Opus 17 and @dmertz on their excellent responses to your specific question, I would just like to add:
(a) while there is article 17 of US-China tax treaty that refers to taxability of pension income allowing the distributor country to tax the income, there is no clearly articulated as to whether the resident country can also tax the same income or not. Obviously if this does happen then " elimination of double taxation" clause will come into focus.
(b) please note that if you have lived in USA as a resident for a longtime ( 7-10 years ), when you leave the country, you will need to get "sailing permit" --- this generally entails US collecting or get assurance of being able to collect taxes due ( and/or may be due at a later date including the use of Mark to Market ).
Hence my general comment would be , if you do plan to leave the USA in the near future ( one to two years ) , consider planning the tax side, simplify / dispose of US holding etc. using the services of a Tax Professional familiar with International Taxation, especially persistence post departure. There are too many "ands" ,"ifs" and "buts", "not-withstanding" etc. in this future scenario. A very careful walk is suggested so as to minimize tax surprises. IMHO
Xie-Xie
pk
