It would be irksome, sure. But there is no amount of weaponry that China could supply Cuba with that would threaten the USA (short of nukes), so it would be a moot point. Business as usual. Taiwan similarly has no hope of success in attacking China, regardless of how many weapons the USA provides. Meaning: this only works one way, and if China is upset about that then maybe they should keep their eyes (and hands) within their own borders and everything will be fine.
It would be irksome, sure. But there is no amount of weaponry that China could supply Cuba with that would threaten the USA (short of nukes), so it would be a moot point. Business as usual. Taiwan similarly has no hope of success in attacking China, regardless of how many weapons the USA provides. Meaning: this only works one way, and if China is upset about that then maybe they should keep their eyes (and hands) within their own borders and everything will be fine.