Russia, has given up control over 700,000 square miles of valuable territory. The other, the European Union, has gained control over 400,000 of those square miles. Which of these powers is expanding?There remain 300,000 neutral square miles between the two, mostly in Ukraine. From Moscow’s point of view, this is already a grievous, irretrievable loss. As Zbigniew Brzezinski, one of the canniest of the old Cold Warriors, wrote back in 1997, ‘Ukraine… is a geopolitical pivot because its very existence as an independent country helps to transform Russia. Without Ukraine, Russia ceases to be a Eurasian empire.’This diminished Russia feels the spread of the EU and its armed wing, Nato, like a blow on an unhealed bruise. In February 2007, for instance, Vladimir Putin asked sulkily, ‘Against whom is this expansion intended?’I have never heard a clear answer to that question. The USSR, which Nato was founded to fight, expired in August 1991. So what is Nato’s purpose now? Why does it even still exist?