Secret documents show the UK government wanted to hand over the "feudal" Falkland Islands to Argentina only 14 years before they were invaded.
A junior Foreign Office minister was scathing about the islanders he met on a visit in November 1968 and their "fossilised attitudes", according to a report.
Lord Chalfont was trying to win over hostile local opinion in the South Atlantic outpost, which he described as "violently anti-Argentine", while secret talks were under way with the Argentine government about a possible handover.
Lord Chalfont toured farms and settlements on the six-day visit to the islands, population 2,000, never previously visited by a British minister.
His mission was to persuade the 2,000 "unsophisticated" and suspicious islanders of the economic benefits of closer ties with Argentina, "leading gradually but inexorably to the acceptance of Argentine sovereignty". But he stressed how the Government "must avoid at all costs giving the islanders the impression that we want to get rid of them".
Lord Chalfont broke the government's plans to the island's executive council, emphasising that there would be no transfer of sovereignty to Argentina against their wishes.
The news was greeted with a stony silence and a threatened unanimous resignation. "Intemperate" councillors in heated discussions described the move as "a betrayal and a stab in the back".
He wrote in his withering assessment that the society had a "paternalistic, almost feudal character which has not existed in any other English-speaking country since the turn of the century".
Lord Chalfont described the islands as being cut off from the rest of the world, with a failing economy based on sheep farming, and no secondary education beyond 15.
PA