Less than two weeks after the Argentinian invasion on 2 April 1982, Thatcher described a “diplomatic solution” as being “a considerable prize”. She was responding specifically to a plan whereby in return for withdrawing its troops Argentina would be represented on an interim commission and on Falkland Islands councils.

Francis Pym, the foreign secretary, is recorded as saying: “It would be a remarkable achievement if this could be brought about, at a time when Britain’s military position was still weak.”

Asked in private evidence to the subsequent Franks committee of inquiry about her reaction to the invasion, Thatcher said: “I just say it was the worst, I think, moment of my life,” the papers reveal. Asked if she was prepared to cede sovereignty over the islands if the islanders agreed, she replied: “Yes”.