We have historic evidence of what happens when a country with nukes uses them against a country without them on large population centers….war over. And the rationale for doing so was that the country without nukes would fight to the last man…they even had their own version of suicide bombers.
All that being said your last sentence is the real key. Negotiate a deal with China such that it’s not worth it to support them...Iran collapses. If it’s just business, address the business motivations.
