alt Hacker NewsThe Soviet Union's relationship with China was more of a peer rivalry situation. The Russian relationship with China is nowhere near parity. Russia would fold tomorrow if China withdrew their backing and went along with the US/EU sanctions.
So Russia is only able to prosecute their war with China's permission. When your foreign policy is decided by another power, that's the textbook definition of a vassal.
It's not a binary choice between material support and sanctions, there are plenty of intermediate states. I think you are being hyperbolic again.
And I disagree that USSR and PRC were just "rival peers". Rival peers would be UK/US (at least until Suez), or UK/FR until the 90s. USSR and PRC actively fought each other and almost started a nuclear war; that's way beyond "peer rivalry", that's actual direct competition.