Putin sees the fall of the Soviet Union as a ‘catastrophe of the century’ which has left Russia vulnerable on its western border where it once had client states like Poland, East Germany and Czechoslovakia and now has countries which have joined the EU and NATO. Russia wants these buffer states to protect itself from invasion from the west, mindful of the terrible suffering it endured when the Nazis invaded in 1941, resulting in the death of around 28 million Soviet citizens.