I WANT, as Max Bygraves would put it, to tell you a story. And as the story eventually gets round to mentioning Israel, I’ll have to tell it very carefully.

You see, I know that just by mentioning that country I’ll be getting endless e-mails about the dreadful King David Hotel bomb, and policy in Gaza. And usually I don’t mind. These are legitimate points and I think I have answers. It’s just that if I get these e-mails this time I’ll know I haven’t told the story properly. I’ll know that my point has been missed.

My story is about something that happened 60 years ago this week, an interesting little postscript to all the D-Day anniversary coverage.

In July 1944 the Americans made an extraordinary proposal to the British. Noting the many Germans interned or under house arrest in Latin American countries, and noting, too, that thousands of concentration camp inmates were Latin American citizens or dependants, they proposed a swap. They hoped to persuade the Germans to agree.

First, however, the idea had to get past the British Foreign Office. In order to draw up a long enough list of detained Germans, British help was needed. And that support was not forthcoming. Now there was, let’s be fair, a legitimate reason for the Foreign Office to be wary of the American idea. It was concerned that any returned Germans would aid Hitler’s war effort. “Many have qualities that would render them of considerable value to Germany,” wrote the British Ambassador in Uruguay to his colleagues. “It seems absurd to suggest sending to Germany . . . highly trained employees of the German bank who otherwise are languishing here doing nothing but draw their pay.”

Given what the Foreign Office knew about starvation and murder in the camps, this argument hardly suggests an organisation rising to the moment. But it was at least defensible.

Sadly, it wasn’t the real reason why the British Government opposed the swap. Amazingly, it wasn’t the return of the Germans that worried them most. It was the release of the Jews.

This is what Anthony Eden wrote to one of his diplomats and it explains it all. It’s a letter that I’ve had to read several times to check if I understood it properly:

“Most of the holders of these documents [the Latin American passports of camp inmates] are of Jewish race who have been accepted as immigrants to Palestine, and the passports are good for a journey thither provided the holders succeed in leaving enemy or enemy-occupied territory. In these circumstances it appears doubtful that it will ever be possible to carry out the exchange envisaged by the United States Government.”

I think I have understood it properly. Eden would rather the Jews died in concentration camps than go to Palestine. And, in case you were wondering, he did know that, in all likelihood, the Jews he was leaving there would die.

By the beginning of 1945, the American end of the correspondence was getting even more desperate. They had succeeded, even without Eden, in arranging at least one exchange. And now the State Department wrote to the British Ambassador in Washington, Lord Halifax, to tell him of “the most distressing reports regarding physical conditions of the unfortunate persons from Bergen-Belsen camp who were released in the latest exchange of civilians, and it will be noted that five of them died of malnutrition during a short period after their arrival in Switzerland”. They might have added that those who survived were shipped off to a refugee camp in Algeria.

The Americans cautioned that thousands of others faced certain death unless more was done. The British position remained unchanged.

I’m telling this story for a number of reasons, but one of them is to help to understand what’s going on in the Middle East. If you ever wonder why Jews all over the world support Israel and believe that they wouldn’t be safe without it, then this story might help you to comprehend; and it provides an insight, too, into the reasons why Israel, wrongly or rightly, obstinately trusts its own judgment about its security rather than trusting ours.

Remember that I’m not trying to argue about the rights and wrongs of current policy. There are other times for that. I’m just trying to explain something that might seem inexplicable.

There’s a little bit more to the story, too, so let me finish telling it. When Eden’s correspondence was first made public five years ago, some people found it hard to believe. A Professor William Rubinstein wrote to this paper suggesting that the whole incident was far-fetched. The Nazis would have let go anyone with a genuine Latin American passport and killed those with forged documents. And they would never have agreed to the US proposal. It was just an attempt to blame Eden. There was not “an iota of evidence for it”.

Except that there was.

A few days after the professor’s confident claim, The Times printed another letter. It read: “My mother, two sisters and myself were among the handful of prisoners released from Belsen in January 1945. My mother died within hours of her arrival in Switzerland, having brought her three children into freedom.”

The writer’s family had qualified for the exchange because a friend of theirs had managed to buy them a Paraguayan passport. A false document, but good enough to be counted as a foreign passport. There had been “a whole section in Belsen devoted to such prisoners”.

The Nazis had been anxious not to let any sick people on the transport, but, even though she was dying, the writer’s mother had held herself upright long enough to get on to the train.

They hadn’t been going for long when the guards changed their minds. They had too many Jews for the exchange. A guard walked through the compartments throwing people off, many of them to die, freezing in the snow outside. When he got to the writer’s family he told them, too, to get off the train. They pleaded with him that their mother was too ill to move. He shrugged his shoulders and moved on. On such whims were lives lost or saved.

The writer didn’t talk about this last terrible encounter in her letter.

I just know it because she is my mother.

daniel.finkelstein@thetimes.co.uk