The phone call William Burns had travelled halfway around the world to speak with Vladimir Putin, but in the end he had to make do with a phone call. It was November 2021, and US intelligence agencies had been picking up signals in the preceding weeks that Putin could be planning to invade Ukraine. President Joe Biden dispatched Burns, his CIA director, to warn Putin that the economic and political consequences if he did so would be disastrous. Fifteen years earlier, when Burns was US ambassador in Moscow, Putin had been relatively accessible. The intervening years had concentrated the Russian...