The Long Road Home, By Ben Shephard

On 20 August 1940, while the Battle of Britain was still raging and a cross-Channel invasion remained a real possibility, Winston Churchill made a remarkable pledge. When Nazi power was shattered, he told parliament, the victors would bring food as well as freedom to all the countries of Europe enslaved by Hitler, including Germany and Austria. Three years later, Franklin Roosevelt established the United Nations Relief and Rehabilitation Administration (UNRRA) to alleviate the sufferings of "the little men and women who have been ground under the Axis heel". Appointing as its head his political ally Herbert Lehman, the President was heard to say: "I want to see some of those Goddamned Fascists begging for subsistence from a Jew."

UNRRA had the formidable task of looking after and repatriating many millions of displaced persons (DPs) stranded amid the ruins of the Third Reich. There were prisoners of war, fugitives from the Red Army, foreign slave labourers, Cossacks, Ukrainians and Croats who had fought for the Germans, inmates of concentration camps and survivors of the Holocaust – though the unique disaster that had overtaken European Jews was not properly recognised at the time.

The military authorities were overwhelmed by this "tidal wave of nomad people" which submerged cities such as Heidelberg and Frankfurt. Pillage, rape and murder were commonplace. In Hanover, Russian DPs broke open the wine cellar in the town hall, some drowning in the flood of alcohol. A British officer described the scene as something "out of Hogarth or Hieronymous Bosch".

As Ben Shephard shows in this excellent book, UNRRA was not well equipped to cope with such a shambles. It was excessively bureaucratic. Its senior man in Europe, General Sir Frederick Morgan, was anti-Semitic – he described the American Zionist Rabbi Silver as having "the traditional Shylock aspect". Despite high pay, suitable employees were hard to find. A florid British major, asked if he had done any relief work, replied: "Good God, madam, I relieved Mafeking."

Some of UNRRA's functionaries made mistresses of Polish DPs. Others engaged in crime, such as selling supplies on the black market. Still others (including Lehman's feisty successor, Fiorello LaGuardia) assisted illegal Jewish emigration to Palestine. No wonder the acronym was said to mean "You never really rehabilitate anyone."

It was extraordinarily difficult for relief workers to appreciate the hideous experiences which had marked many DPs as indelibly as Auschwitz tattoos. Children evacuated from Buchenwald were found to be "undisciplined, unstable, primitive and even bestial". They did not laugh or play and they were unmoved by tragedies while flying into a rage over trifles. Adults suffered from a "barbed wire complex", morbidly recapitulating episodes of incarceration. Poles were especially anarchic, as high VD rates suggested – at Wildflecken DP Camp in Bavaria, even the girl who played the Virgin Mary in the "Holy Manger" Christmas show had gonorrhoea. Jewish DPs, though plagued by factionalism, sought strength through one scholar has called "a totalitarian conception of unity". They ran their camps on paramilitary lines, complete with uniforms, banners, marches and propaganda.

After the bulk of DPs had been repatriated – sometimes by force and, when their destination was Russia or Yugoslavia, often with fatal consequences – UNRRA was left with a remnant of 1.5 million people, mostly east Europeans, who would not go home. There was much in the way of education, enterprise and self-help. Just as UNRRA triumphantly saved Yugoslavia from starvation and helped Poland towards recovery, it provided DPs with a standard of living that was the envy of Germans – three of whom went so far as to get circumcised and embrace Judaism in order to receive DP rations. Eventually other countries permitted the entry of DPs, America taking the most and preferring Balts to Jews.

This is a complex story and Shephard does not always recount it with crystal clarity. But his research is meticulous. He writes well with a keen eye for detail. His judgements are trenchant and he dishes out praise and blame with an even hand, commending Britain for feeding Germany by rationing bread at home and condemning the "sheer hoggery" of the US military for starving Europe of grain.

What emerges most strikingly is the intricate mixture of motives behind the rescue of post-war Europe. The Allies were by no means pure altruists. At first they were terrified of famine and a pestilence that would sweep across the world as Spanish flu had after the Great War. Later, as the Cold War began, they were intent on restoring Europe to act as a bastion against Communism. This meant letting Germans take charge of their own affairs, a development alarmingly accompanied by a recrudescence of anti-Semitism: a Stuttgart cinema audience cheered when a newsreel mentioned the murder of six million Jews.

Shephard also demonstrates how Ben Gurion used the Holocaust survivors as a means towards the establishment of Israel. Thus a British offer to take Jewish orphans from Germany was rejected on the grounds that it would be a "moral victory" for the nation restricting the entry of Jews to Palestine. No easy path was afforded to the refugees from hell.

Piers Brendon's 'The Decline and Fall of the British empire' is published by Vintage