It was different in Austria and Germany, where voters had been robbed and raped by the Red Army. In the Berlin city elections, the Social Democrats won 63 of 130 seats, the Communists only 26. However, Germany was ruined and starving, and the Kremlin still hoped that the people might turn to Communism in desperation, just as they had turned to Nazism in the Depression.

Britain was the great disappointment. Only one Communist had been sent to Parliament in the postwar election there. And the Labour government was delivering everything Communism promised: welfare, free health care, education for all, even a five-day week for coal miners.

But in the rest of Europe, capitalism was failing to lift people out of the postwar slump.

And the weather was on Stalin’s side, Volodya thought as the layers of snow grew thick on the onion domes. The winter of 1946–7 was the coldest in Europe for more than a century. Snow fell in St Tropez. British roads and railways became impassable, and industry ground to a halt – something that had never happened in the war. In France, food rations fell below wartime levels. The United Nations Organization calculated that 100 million Europeans were living on 1,500 calories a day – the level at which health begins to suffer from the effects of malnutrition. As the engines of production ran slower and slower, people began to feel they had nothing to lose, and revolution came to seem the only way out.

Once the USSR had nuclear weapons, no other country would be able to stand in its way. Volodya’s wife, Zoya, and her colleagues had built a nuclear pile, at Laboratory No. 2 of the Academy of Sciences, a deliberately vague name for the powerhouse of Soviet nuclear research. The pile had gone critical on Christmas Day, six months after the birth of Konstantin, who was at the time sleeping in the laboratory’s crèche. If the experiment went wrong, Zoya had whispered to Volodya, it would do little Kotya no good to be a mile or two away: all of central Moscow would be flattened.

Volodya’s conflicting feelings about the future took on a new intensity with the birth of his son. He wanted Kotya to grow up a citizen of a proud and powerful country. The Soviet Union deserved to dominate Europe, he felt. It was the Red Army that had defeated the Nazis, in four cruel years of total warfare: the other Allies had stood on the sidelines, fighting minor wars, joining in only for the last eleven months. All their casualties put together were only a fraction of those suffered by the Soviet people.

But then he would think of what Communism meant: arbitrary purges, torture in the basements of the secret police, conquering soldiers urged on to excesses of bestiality, the whole vast country forced to obey the wayward decisions of a tyrant more powerful than a tsar. Did Volodya really want to extend that brutal system to the rest of the continent?