Last week, after two car bombings, no one wanted to rock the boat and distract the search for suspects by bluntly criticising MI5, the security service, in public. But in private Arabs and Jews were saying the same thing: the British did not listen.
According to the only public statement that MI5 has ever given, the idea that an apparently experienced terrorist could drive a stolen car into the street next to the embassy - one of the most heavily protected buildings in London - park and walk away leaving a bomb behind, was absurd.
Stella Rimington, its director general, proudly stated in her Dimbleby lecture on 12 June that the security service had made a significant impact in the fight against Middle East terrorists operating in London.
'We have helped to prevent the intelligence services of a number of Middle Eastern states from carrying out campaigns of murder against opponents in this country,' she said.
Last week, Middle Eastern diplomats were recalling her words and strongly criticising MI5 and MI6 for their 'old- fashioned approach' to modern terrorism.
'They (MI5 & MI6) were only concerned with dealing with individual terror attacks or someone like Colonel Gaddafi or Saddam Hussein sending an assassin to kill an opponent in London,' said one diplomat. 'Beirut-style car bombs are different and they were not ready for them.'
He and Israeli officials criticised the 'relaxed' attitude of the security service to information about possible attacks from Islamic extremists.
'They thought London was a difficult target for a terrorist attack from our part of the world,' said an Arab intelligence officer arriving in London last week to help MI5 and the police find the bombers, 'but there are too many fish swimming in a very large pond . . . London has become an Arab capital, my friend.'
Just how many fundamentalist opponents of the Israeli/PLO deal there are in London now, and how many of them would be willing to go beyond legitimate criticism of a settlement that leaves hundreds of thousands of Palestinians homeless, is the subject of bitter controversy.
A year ago MI5 was told by Mossad, the Israeli intelligence service, that Britain had become a major base for Hamas leaders who had direct links with murder squads.
The claim followed the arrest of two high-ranking Hamas operatives, Mohammad Salach and Mohammad Jalad. The Palestinians, with US citizenship, had passed through London carrying dollars 600,000 ( pounds 400,000) for rebuilding the organisation after Israel expelled more than 400 Hamas members to Lebanon.
Israeli sources said then that the men were briefed in London by a senior Hamas agent before leaving for the West Bank. The agent, whose name is well known to British intelligence officers, continues to live in London and operate freely.
British Jewish organisations, most notably the board of deputies, backed the Israeli calls for Hamas and Hizbollah to be labelled as proscribed organisations under the Prevention of Terrorism Act.
They lobbied John Major and Michael Howard, the Home Secretary, to have the law changed.
By the spring of this year, the demands had become insistent. Two suicide car-bomb attacks in Israel - one in September 1993 and one in April this year, which left 12 dead - led some MI5, MI6 and Scotland Yard officers to share the Israeli concern.
According to an Israeli Radio report at the time, which was based on an intelligence leak, Israeli and British officials started working together to have Hamas declared a terrorist organisation in Britain.
But no ban came. British officials defended their decision by saying that the Israelis had cried wolf many times in the past.
A successful intelligence strategy should be based on specific warnings about specific crimes rather than general bans on organisations the Israelis did not like, they added.
Hamas and Hizbollah may be fighting the Israelis and PLO leadership in the Middle East but that did not automatically mean they were planning crimes in London.
When Jordan, Egypt and other Arab countries joined the Israelis in criticising the British authorities, Britain's response was that they were trying to get the Government to silence troublesome exiles in London. 'Arab regimes just wanted Britain to censor their Islamic opponents who make use of the atmosphere of free speech in Britain,' said one British official.
The Foreign Office's words are now being thrown back in its face by both Jews and Arabs.
'We have been urging the British for years to keep an eye on these people but they are too relaxed,' said one Arab diplomat who complained that his embassy's reports about Muslim fundamentalists active in Britain were not taken seriously. 'But they replied, 'You just want us to silence your opposition' and then gave me a long lecture about freedom of expression.
'They failed to realise the simple fact that violence is commonplace for these organisations. It is violence and terrorism in different forms and different degrees, whether intimidating a woman to force the veil on her face, or burning down a theatre that performed something they (Muslims) consider anti-Islamic, or shooting a writer who authored a book considered blasphemous, or blowing up an embassy - all are the same.'
Last week, the stream of allegations about ignored warnings came to a head when the World Jewish Congress claimed that Argentina had told Britain that the investigation into the murder of 96 people in a car bomb at the Beunos Aires Jewish community centre on 18 July suggested that London could be a target.
Intelligence services often blame each other when something goes wrong. But support for the claim of British insouciance in the face of a growing threat comes from the board of deputies, which represents most British Jewish organisations. Members went to Scotland Yard and raised concerns about security in numerous meetings with the Home Office and Prime Minister's Office.
Mike Whine, the board's security officer, said that 'you did not have to be James Bond' to work out that attacks were likely. Reports in the Lebanese press and from the BBC international radio monitoring service at Caversham had spoken repeatedly of the threat of bombings in Northern Europe.
'Our friends in Europe were telling us that there were armed police guards outside synagogues,' he said. 'I don't want to be critical of the Metropolitan Police, but there does seem to have been some problem with the people they pass their information on to.'