The United States had no warning of the attack on the Osirak reactor ordered by Menachem Begin, the Israeli Prime Minister, in June 1981 amid fears that Saddam Hussein was trying to build a nuclear weapon.
Files released by the National Archives show that Britain's ambassador to Washington, Sir Nicholas Henderson, was with US Defence Secretary Caspar Weinberger as the news came in.
"Weinberger says that he thinks Begin must have taken leave of his senses. He is much disturbed by the Israeli reaction and possible consequences," Sir Nicholas cabled London.
Britain's ambassador in Baghdad, Sir Stephen Egerton, disclosed that the Iraqis had been just as surprised when the Israeli F15 fighters appeared in their skies.
"The diplomatic corps had a ringside view of the belated ack-ack and missile reactions to the raid when we were gathered for the Italian national day reception on the Bund [waterside]," he wrote.
And a second report:
When news broke that Israeli fighters, flying at dusk from a Negev airbase and crossing Jordanian and Saudi air space, had destroyed Iraq's Osirak reactor, the perceived nuclear threat from Saddam Hussein appeared to have been lifted.
But confidential documents, just released by the National Archive, show that the attack, in June 1981, brought an angry response not just from Saddam but from many of Israel's firmest friends - including the Americans.
US Defence Secretary Caspar Weinberger reportedly said: "[Menachem] Begin must have lost control of his senses."
This less-than-diplomatic outburst was overheard by a British embassy official who passed it on to the Foreign Office, where a similar view was taking hold.
The Israeli raid, by F15 and F16 jets, on Iraq's French-supplied nuclear facility, followed intelligence reports that the reactor was on the point of producing weapons-grade nuclear material - despite Iraqi protests that it was developing nuclear power for peaceful purposes.
"I will not be the man in whose time there will be a second Holocaust," Prime Minister Begin had told his military chiefs.
An eye-witness report on the raid came from the UK's ambassador in Baghdad, Sir Stephen Egerton.
In a "secret" cable to Whitehall he described how "at 18.34 local time, enemy aircraft, later shown to be Israeli, bombed the Osirak reactor.
"They flew in low at dusk from the Western Desert, and to avoid the enormous earthworks surrounding the reactor, they climbed sharply and then precision-bombed their target." World reaction to the operation - codenamed Operation Opera - was a mix of shock and dismay, the documents revealed. Despite some comments that displayed thinly-veiled respect for the audacity of the Israeli pilots, even Israel's traditional friends were furious.
After much debate, the US voted in favour of a UN Security Council motion condemning Israel's actions and it also delayed the delivery of a consignment of jet fighters to the IAF. This followed successful diplomatic efforts by the West to persuade the Iraqis and their Arab allies not to push ahead with a resolution demanding tough economic sanctions against Israel.
"Clearly, it would be right to avoid sanctions," said a Foreign Office official in a report to Britain's prime minister, Margaret Thatcher.
This was essential, he added, if America was to support the resolution - something that would have "real impact on Israel".
One staffer at the British UN mission, in a message to Downing Street, said that America's UN Ambassador Jeane Kirkpatrick was under particularly heavy pressure "from the Zionist lobby". The official added: "I know this for a fact. She has bared her soul to me."
Known for her sterling support of Israel, Mrs Thatcher was also urged by lobbyists to understand Israel's actions. She dismissed their arguments as "unsupported".