The Falkland Islands Co. - a London-based fishing corporation - withdrew its supply ship to Montevideo, which cut-off the islanders from receiving mail service. Britain told the islanders it was not economically feasible for them to continue to receive mail.
At the request of the World Postal Union, the Argentine Air Force began a weekly mail flight (at no cost) using a float plane (Malvinas had no airport at the time), to Islas Malvinas to supply the islanders with mail so they would not become the most isolated place on Earth. The RAF had previously refused a similar request from the WPU. Argentina also provides free medevac flights to Buenos Aires for ill islanders.
Argentine Air Force began to take its Albatross long-range amphibians out-of-service and informed the UK it would no longer be able to take care of the islanders.The islanders petitioned London to build them an airport. UK: "that's not economically feasible." The islanders petitioned Buenos Aires to build them an airport. Argentina agreed to continue to send welfare payments to the islanders, out of goodwill, and paid for construction of a rough airstrip. Continues operating free postal and medevac flights.
Argentina and the local government jointly fund construction of Port Stanley Airport. Britain is invited but doesn't bother to send any representatives to the opening ceremony of the airport. The airport, instead, is ceremonially opened by the Governor of the "Falklands" and the Vice-President of Argentina who flies in for the event.
The UK passes the British Nationalities Act, which strips the "Falklanders" of British citizenship.
This was not a thriving, economically self-sustaining outpost. This was a patch of dirt inhabited by a group of people who were barely hanging on and utterly dependent on Argentine charity to survive.