everything you say is true of all 190+ countries: they all knew what a continuation of russia's genocide of Ukraine would cause, and yet each one did nothing despite being capable of sending at least minimal aid to Ukraine, or publicly voicing opposition to russia's genocide of Ukraine
so, again, each of those countries (russia alone more than any other) is equally guilty, be they China, USA, Iran, Canada, North Korea,
etc: none had any responsibility to intervene more or less than the others, and EU receives no special blame for russia's genocide of Ukraine
or, more to the point, they are all equally innocent, except for the aggressor, russia, who started the genocide of Ukraine in the first place
so, again, each of those countries (russia alone more than any other) is equally guilty, be they China, USA, Iran, Canada, North Korea, etc: none had any responsibility to intervene more or less than the others, and EU receives no special blame for russia's genocide of Ukraine
or, more to the point, they are all equally innocent, except for the aggressor, russia, who started the genocide of Ukraine in the first place
tl;dr russia is to blame