At least since Obama.
https://en.m.wikipedia.org/wiki/East_Asian_foreign_policy_of_the_Barack_Obama_administration
Here's an EU based article saying that really it's been happening since Clinton.
https://ecpr.eu/Events/Event/PaperDetails/25139
Always as in before anyone currently in power was in power.
Now, China is just saying what your thinking. If EU isn't supporting USA on this, we can talk. Otherwise what do we gain from not keeping Russia afloat?
Edit btw the point of all of this is China is literally telling the EU how to stop the war. Turn on the US
That was a paper talking about history. That it started before Obama even. Though, as the wiki article states at a minimum it started with Obama. Also, why would Russia lose? The implied threat is your going to be facing down J20s if it gets bad enough.