The real countries in reduce war equation were Germany and France, not Russia.
The real countries in reduce war equation were Germany and France, not Russia.
On the other side, I suspect that none of the existing EU members would be happy with having a new one that's so much larger in population than any of the others that it'd gain effectively a veto power over everything, to say nothing of the domestic political issues with potential east-to-west migration.
It could, however, by 2013 have massive students exchange, Schengen visa waiver programme for short visits, cultural exchange, etc. None of that happened. EU just wanted oil & gas and unilaterally accept some of the brighter students into their universities, ideally having them pay for that privilege.
EU also wanted to "euroassociate" our neighbour countries, where they will get no guarantees or support of being EU member, but would open their markets to the EU and half-shut their markets, and borders, towards Russia. That was a directly hostile move towards Russia, who was completely shut off these arrangements.
EU and USA were also openly nagging Ukraine to boot Russian naval base from Crimea. A directly hostile move which backfired quickly and led to the whole war thing in the end.