As has already been pointed out, you cannot trust what the Americans say, only what they do.
Indeed, actions speak louder than words. It's what American do that counts, not only what they say.
But now that the die has been cast, Putin can see that NATO truly has zero appetite to challenge him so, and can thus adjust his planning and calculus accordingly.
Nobody expected NATO to intervene. US gov't sending merely 5000 US troops reinforcement to Poland/Baltics is insufficient to fight a 200,000 Russian invasion of Ukraine. Putin likely saw such a weak reinforcement as congruent and consistent with US public statements.
Any joint venture developments would automatically give China a veto on sales if it cared enough about it.
So China should engage in joint venture of Checkmates and Su-57 to have a veto on it. Why not use it's China's economic influence on Russia to have a veto? Or would that be too insulting for Russian ego to be dictated by China on export sales? If that's the case, then offer to give Russia $10 billion to not export Su-57 or Checkmates to India/Vietnam, so Russia can still sustain it's weapons industry and still invest in R&D in innovative technology.
Also, as Russian economic integration with China increases, it should naturally diversify and expand their economic base where weapon sales become far less important economically.
I hope Chinese trade and investment via BRI/AIIB can wean Russia off it's dependence on oil and weapon exports and diversify it's economy to become more stronger to withstand pressure from West and restore it's economy to Great Power status.
But at the end of the day, Russian arms sales to Vietnam and India doesn’t really threaten China.
Fair enough.
Just don't say China-Russia relationship will develop akin to US-UK 'special relationship' when they are selling top arms to SCS dispute claimants.
And to be frank, it’s better they buy Russian weapons than western ones.
This is a false dichotomy. It's better they try to buy neither Russian or Western ones, but try to innovate themselves (good luck!).
Did US say: "Israel should sell Phalcon AWACs to China because better Western AWACs than Russian AWACS?" No, US thought it's better if China tried to innovate AWACs themselves, and just incorrectly assume Chinese can't innovate indigenous alternatives. However, I am willing to make the bet that India/Vietnam will not have indigenous 5th gen options in my lifetime or ever.
