[hetman]

Your thesis assume that Eastern European countries were fully on board with Soviet ideology until the fall of the Soviet union. In fact, most of the Eastern European nations had been forced into the Soviet sphere of influence against their people's will. Multiple popular protests that were brutally crushed by Soviet aligned militaries suggests the discontentment never went away. So I don't think the ideology in those Eastern European states needed to shift significantly after that fall of the USSR. The EU didn't need to conquer Eastern Europe because their people wanted to align themselves with Western Europe all along.