The Russians signed it and then completely ignored the agreement.
That is an objective fact and has nothing to do with the rest of the cultural relativism you're engaging in.
Whataboutism about the US _not signing_ things is also irrelevant.
The whole AI treaty discussion is about a treaty countries will _actually sign_ and the relevance of Russia cheating on the BWC is that the signatures of some countries are absolutely worthless, which _is_ relevant.