Can Russia’s past be overcome in order to achieve unity?

It appears that one of the greater obstacles keeping Europe, specifically Russia, from uniting is that Europeans seem to have a difficult time overlooking blemishes in their pasts. For example, people still question, current Russian President, Vladimir Putin’s past in the KGB. Many Russians, along with other countries as well, question Putin’s “soul” and character due to his involvement in the KGB many years before (Myers).
If citizens within a country cannot come to terms with a person’s past, how can forty individual countries be expected to overcome the negative events between one another in their pasts? This is just one example that shows how a country’s past, whether a specific war or president, can impede Europe from unification. If people cannot get over another country’s dark past, or remove a grudge from 5 centuries before, how do people expect them to unite to a single European Union? I do not believe that we can expect that to happen easily, if at all, ...