It is not clear if there are other countries other than the EU that can influence the situation(aside the US and Russia).

I’ll be the first to admit I am very ignorant about the geopolitics of this war, but how can this possibly be true? India could stop trade relations with Russia; China could invade Russia; the global south could conscript and send armies to support Ukraine. I’m not saying these countries would or even should do these things, but isn’t an analysis self-defeating if we just assume only EU & US have any influence?

Sir, that is the definition of a rhetorical question.