The biggest obstacle to shifting Israeli and western perceptions of 1948 has been the lack of a clear paper trail connecting the political leadership to the massacres. Israel locked away bundles of documentation precisely not to jeopardise the official narrative.

But things are changing slowly.

Last year a key deception was punctured: that Israel urged many of the war’s 750,000 Palestinian refugees to return. In a letter to Haifa’s leaders shortly after the city’s Palestinians were expelled, David Ben Gurion, Israel’s first prime minister, demanded that any return be barred.

Now another letter, located by Israeli historian Yair Auron and published last week for the first time in English by the Haaretz newspaper, trashes the idea of an ethical Israel army.

Written by Shabtai Kaplan, a soldier and journalist, the letter confirms long-held suspicions of a massacre – one that dwarfs Deir Yassin – at Dawaymeh, near Hebron. Soldiers executed hundreds of men, women and children who offered no resistance.

The massacre, near the end of the war, was carried out by elite troops under the command of Yitzhak Sadeh. He developed the Israeli army’s famous doctrine of “purity of arms”.

Kaplan argues that the Dawaymeh massacre was part of “a system of expulsion and destruction”, with a clear goal: “The fewer Arabs who remain, the better.”

Kaplan’s letter was consigned to the vaults, as were so many other documents from 1948 that officials considered too damaging.