Margaret Thatcher admitted that she did not anticipate the Falklands crisis and was taken by surprise when Argentina invaded the disputed Islands in April 1982, according to documents released on Friday.

The invasion sparked a war that Britain won massively, boosting her popularity.

“I never, never expected the Argentines to invade the Falklands head-on. It was such a stupid thing to do, as events happened, such a stupid thing even to contemplate doing”, said the then Conservative Prime Minister, a few months after the war ended.

Giving evidence to the Falkland Islands Review Committee, chaired by Lord Franks, whose full transcript has been made public for the first time, she said: “You can imagine that turned a knife in my heart, that lot.”

Describing it as the “worst moment” of her life, Mrs Thatcher said: “That night no-one could tell me whether we could retake the Falklands — no-one. We did not know — we did not know.”

One historian described the documents, released at the end of the 30-year embargo, as among the “most powerful material” declassified in the last three decades.

Though the crisis had been building up for sometime, it was barely two days before she was shown the “raw intelligence” that she thought an invasion was likely. But by then it was too late — and on April 2, Argentina occupied the Islands. A two-month long war ensued, ending with the surrender of Argentine forces in June. The then Foreign Secretary Lord Peter Carrington was widely accused of ignoring the warning signals in the run-up to the invasion and was forced to resign.

He told the Franks Committee: “I have been accused, and was accused violently after April 2 in the House of Commons, and in the press and elsewhere — of wilfully ignoring signs and statements and evidence, and just ignoring it. I can truthfully say I did not do any of these things… they [the signs] were not there.” The war soured relations with the U.S., which was suspected of backing the Argentinian claim to the U.K.-administered Islands.

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