NATO will do the same if it happen... if they have asked for something it's for trucks and ltv. They lost a lot of them. In the ammo category, maybe Katyusha rockets but It's probably a no go....
NATO is NOT waiting for an excuse and pre-text to actually step in with their Air Force, and they will do NO such thing just in response to Chinese actions.
In fact, they will seize the change to bicker back and forth with China and Russia, and threaten sanction on China.
Frankly speaking, the US is already sanctioning all Chinese companies on the US stock market, demanding they turn in their detailed internal financial reporting for US auditing. This is already hurting Chinese stock market really badly (although China is not a real free-market economy, so stock market in China does NOT indicate the overall performance of Chinese economy as much as in the West).
I think this will be a perfect chance to smack the US in the face.
My idea was that they don't go in for a long time. They only join as part of a offensive op. on Kharkov. Go bomb it for 24 hours. Drop as many PGM as possible. Then pull out. It will take a while for the US to notice and confirm. and since Russian positions are very far away from Ukraine-NATO border, they will NOT be able to retaliate sneakily, in equal response.
In fact, I can see the aftermath being first an intel confusion for a couple of days, then heated diplomatic exchange, then angry gestures of military equipment doing "close fly-bys" and "right on the red line" teaser moves, follow by more economic retaliations back and forth.
I am not advocating for this. I am just saying that this is a possibility.
