When Vladimir Putin called the collapse of the Soviet Union ‘a major geopolitical disaster of the century’ he wasn’t channelling his inner Marxist-Leninist. Russia’s leader is not interested in remaking the Soviet empire, which finally fell apart 30 years ago today, on Boxing Day 1991. But he does want to roll back the losses of the post Cold War era, expand Russia’s sphere of influence, and build a buffer zone around the homeland.