“The object of the exercise was to get some rocks which will remain ours”. - Permanent Under Secretary at the Foreign Office, secret file of 1966.

Declassified UK Government files reveal the concerns and priorities of British ministers and officials in the late 1960s and early 1970s. They also reveal the beginnings of a Whitehall strategy, which continue today. 

The Colonial Office stated that the "prime object of BIOT exercise was that the islands . . . hived off into the new territory should be under the greatest possible degree of UK control". The islanders were to be "evacuated as and when defence interests require this", against which there should be "no insurmountable obstacle", the Foreign Office stated.

Secrecy was seen as vital. A Foreign Office "memorandum of guidance" of May 1964 noted that:

“These steps (ie, the depopulation) should be ordered and timed to attract the least attention and should have some logical cover
where possible worked out in advance. Even if these steps are taken with the utmost discretion and careful planning we must anticipate that they will become known and arouse suspicions as to their purpose.”

Seven years later, a Foreign Office minute reads: "In the matter
of the Illois, there may be an awkward problem of presentation. Meanwhile, the less said the better" .

The Chagossians were described by a Foreign Office official in a secret file: "unfortunately along with the birds go a few Tarzans and Man Fridays who are hopefully being wished on Mauritius".

According to the Foreign Office, "these people have little aptitude for anything other than growing coconuts". The Governor of the Seychelles noted that it was "important to remember what type of people" the islanders are: "extremely unsophisticated, illiterate, untrainable and unsuitable for any work other than the simplest labour tasks of a copra plantation" .

Population, what population?

“We would not wish it to become general knowledge that some of the inhabitants have lived on Diego Garcia for at least two generations.” - Permanent Under Secretary at the Foreign Office 1966

The strategy was to ‘present to the outside world a scenario in which there were no permanent inhabitants on the archipelago’. One official stated:

One official noted that British strategy towards the Chagossians should be to "grant as few rights with as little formality as possible". In particular, Britain wanted to avoid fulfilling its obligations to the islanders under the UN charter.

A British Foreign Office memo of 1970 stated: “We would not wish it to become general knowledge that some of the inhabitants have lived on Diego Garcia for at least two generations and could, therefore, be regarded as 'belongers'. We shall therefore advise ministers in handling supplementary questions about whether Diego Garcia is inhabited to say there is only a small number of contract labourers from the Seychelles and Mauritius engaged in work on the copra plantations on the island. That is being economical with the truth”.

A secret document signed by Michael Stewart in 1968, said: "By any stretch of the English language, there was an indigenous population, and the Foreign Office knew it". One Whitehall document was entitled: "Maintaining the Fiction". A Foreign Office legal adviser wrote in January 1970 that it was important "to maintain the fiction that the inhabitants of Chagos are not a permanent or semi-permanent population".