From article: Paying tribute to the East Berliners who pushed past border guards to flood through the Wall on Nov. 9, 1989, Obama said in a statement Friday that "as Russia's actions against Ukraine remind us, we have more work to do to fully realize our shared vision of a Europe that is whole, free and at peace."
I believe Ukraine was a premeditated trap for Russia to step in as a payback from Obama for Syrian embarrassment.