The week in radio: Home truths in a heartbreaking tale of the child victims of war

"I must go to bed now as we have an early start in the morning," wrote 12-year-old Joyce Henderson in her diary on 31 Aug 1939. "Tomorrow, I become an evacuee and it's all because of something called war."

Operation Pied Piper was the code name given to the evacuation of three million British children into the countryside as German troops crossed the border into Poland at the start of the Second World War. It was also the title of a devastating documentary, assembled from the testimonies of those children who were uprooted from their homes, alongside assorted historians on Radio 2.

Radio 2! I know! It's bizarre and, of course, rather wonderful, that the station known for its decaying DJs and old-school playlist should see fit to squeeze this Saturday night tearjerker into its otherwise rigid schedule in honour of Remembrance Sunday. If only it would break with routine more often then perhaps people like me wouldn't lunge for the off-button, sending animals and children flying in my wake, whenever I stumble across Ken Bruce offering faux commiserations to another Popmaster failure, or Jeremy Vine declaiming about the NHS.

But Operation Pied Piper was something else. It ripped your heart out, jumped up and down on it and then handed it back all bruised and misshapen. As is proper at this time of year it reminded us what pampered numbskulls the majority of us really are, having never been required to bear arms; to shut ourselves in a bomb shelter and emerge to find a crater where our home was; to be dragged, screaming and crying, away from our parents to the safety of the countryside, which for many turned out not to be safe at all but a place where they were neglected and abused.

The real genius of this documentary was to use children's voices to recount these memories, with the now elderly evacuees taking over after a minute or two. The effect was to allow us to see these events that much more clearly through the eyes of those who lived through them. Even more disturbing was that it asked us to imagine our own offspring going through the same ordeal. Listening to Operation Pied Piper, I was a heaving mess of snot and tears.

We heard of youngsters vomiting in fear as they were led on to the trains and bigger children jeering "Baby! Baby!" as they wept. We were told of country kids yelling at the new arrivals: "Vaccies go home!" and of a girl chastised for bed-wetting by her host family and being sent to sleep in the dog kennel with a chain around her neck.

We discovered that there was no matching of foster families with children. Instead, adults would walk along the rows of evacuees having been told to "pick your child". Invariably, the pretty girls would go first, along with the strong boys who could help out in factories and farms. Spindly kids with glasses didn't stand a chance.

And you know those classic archive shots of children smiling out of train carriages while clutching teddies? Pure propaganda. Evacuees' luggage was strictly vetted and toys were not allowed. So press photographers would hand out teddies to the youngsters, tell them to say cheese, and take the teddies back once they'd got their shot.

There were happier tales amid the trauma but it was, naturally, the grim ones that haunted you. Oh, I know it's easy to pluck at the heartstrings with stories of sad children – Operation Pied Piper did this without blinking. But these are terrible snapshots of terrible times that should never be allowed to curl and fade.