The plot, we are told, was hatched in Britain. The plotters, we are told, are mainly, if not all, Britons of Pakistani descent. British police and officers of the British security service, MI5, had watched them for many months.

Yet in the 24 hours following the arrests in Britain and the security alert, which caused havoc at British airports, we appear to have learned more from the US than from our own responsible authorities here.

The surveillance, bugging and phone tapping exercise, which led to the arrests of the suspected plotters, was called Operation Overt, according to US sources - clearly named by someone with some sense of humour.

"Martyrdom" tapes were found in some of the houses raided in Birmingham, High Wycombe, and east London, according to the Americans. One of those arrested was the original informer, according to a report in the US media.

The US media confidently asserted that the plotters were divided into three separate cells, and it named individuals it claimed were the key plotters.

Finally, the US security and intelligence agencies claimed the credit for intercepting a message from associates of the plotters in Pakistan and the plotters in Britain which triggered the arrests and warned that an attack was imminent, the US media reported.

Pakistan was also quick get in on the act - and you can scarcely blame it given the stick it (understandably) continues to get from Afghanistan and US and British military commanders for not doing enough to rein in Taliban supporters. Pakistan government spokesmen have been quick to talk up their country's role in defeating and exposing the alleged terror plot. They revealed that they had made arrested some individual a few weeks ago, and then some more a few days ago, and then some more today. All the arrests, they suggested, were linked to the plotters in Britain.

The US media are given information by their security and intelligence agencies - the FBI and CIA - which are passed on details about the plot by their British counterparts, MI5 and MI6.

But they get things wrong because US agencies want to exaggerate the dangers or simply get things wrong. They are guilty of - or victims of - Chinese whispers.

For example, US agencies muddled up the names of individuals linked to the 7/7 suicide attacks in London, and named perfectly innocent people. Two years ago, in 2004, with the help of Pakistan, they released claims of a terror plot, which they knew had been foiled three years earlier.

Unnecessary British caution and secrecy helps the US to claim the credit - and get things wrong.

John Reid, the home secretary, told a news conference this morning that while the police were confident that all the main suspects in the alleged airline bomb plot were in custody, he admitted the authorities could "never be certain". He added: "We always err on the side of caution."

But not when it comes to describing the nature of the alleged plot and its potential consequences: death, as Mr Reid called it on Thursday, on an "unprecedented scale".

Now we await the evidence.