When the UK authorities brought various accused terrorists into custody, American sources said that the bad guys had been mere days away from a dry run. That is, a 9/11 type event was narrowly averted. But how close were they, really?

Some critics say that the evidence from the UK is weak, and the evidence from Pakistan unreliable:

Imminent threat? They had no bombs, no labs, no tickets, and no passports.None of the alleged terrorists had made a bomb. None had bought a plane ticket. Many did not even have passports, which given the efficiency of the UK Passport Agency would mean they couldn’t be a plane bomber for quite some time. What is more, many of those arrested had been under surveillance for over a year … Nothing from that surveillance had indicated the need for early arrests.

Then an interrogation in Pakistan revealed the details of this amazing plot to blow up multiple planes - which, rather extraordinarily, had not turned up in a year of surveillance. Of course, the interrogators of the Pakistani dictator have their ways of making people sing like canaries… Trouble is it always tends to give the interrogators all they might want, and more, in a desperate effort to stop or avert torture. What it doesn’t give is the truth. [Link]

Much to my surprise, even security hawks like Andrew Sullivan have voiced skepticism:

So far, no one has been charged in the alleged terror plot to blow up several airplanes across the Atlantic. No evidence has been produced supporting the contention that such a plot was indeed imminent. … Remember: the British authorities had all these people under surveillance; they did not want to act last week; there was no imminent threat of anything but a possible “dummy-run,” … How could they even stage a dummy-run with no passports? [Link]

Meanwhile, some chemistry geeks have also voiced skepticism about how easily a TATP bomb could have been made on the fly, as it were:

[A bomb would probably involve] … A mix of H2O2 and H2SO4 … When you mix it, it heats like mad …. It is very easy to end up with a spattering mess. You don’t want to be around the stuff in general. Now you may protest “but terrorists who are willing to commit suicide aren’t going to be deterred by being injured while mixing their precursor chemicals!” — but of course, determination isn’t the issue here, getting the thing done well enough to make the plane go boom is the issue. There is also the small matter of explaining to the guy next to you what you’re doing, or doing it in a tiny airplane bathroom while the plane jitters about.

Now, they could of course mix up their oxidizer in advance, but then finding a container to keep the stuff in that isn’t going to melt is a bit of an issue. The stuff reacts violently with *everything*. You’re not going to keep … [it] in a shampoo bottle — not unless the shampoo bottle was engineered by James Bond’s Q. Glass would be most appropriate, assuming that you could find a way to seal it that wouldn’t be eaten. [Link]

The UK government’s past record on such matters is imperfect:

Of those charged, 80% are acquitted. Most of the very few - just over two per cent of arrests - who are convicted, are not convicted of anything to do terrorism, but of some minor offence. [Link]

And the last major alleged plot turned out to be a dud:

The 2 June 2006 Forest Gate raid saw the arrest of two men at their east London homes in Forest Gate by police acting on intelligence that they might be terrorists in possession of a chemical bomb. One of the men was accidentally shot during the raid, but the subsequent inquiries cleared the officers involved of any wrongdoing. No explosive devices were found during the raid. [Link]

America was founded on the premise that citizens should not trust their government too much, and I, as an American have a healthy skepticism concerning what any administration tells me. Still, I hope the root of the whole affair doesn’t end up being a statement like this, made in some Pakistani jail:

“Please stop electrocuting my testicles! What? Only if I reveal a — OWWWWWW — terrorist plot — AAAAAAHH? All right — SCREEEECH! — the terrorists will be blowing up a plane with, with, oh man, I don’t know, hair gel! Yes! Hair gel!”… [Link]

Maybe the whole thing really was cooked up to de-mojofy Abhi’s game last weekend.

Update 1:

The British may have been explicitly pressured by the Americans to move faster than they wanted:

British officials knowledgeable about the case said British police were planning to continue to run surveillance for at least another week to try to obtain more evidence, while American officials pressured them to arrest the suspects sooner…In contrast to previous reports, one senior British official suggested an attack was not imminent, saying the suspects had not yet purchased any airline tickets.

One senior British official said the Americans also argued over the timing of the arrest of suspected ringleader Rashid Rauf in Pakistan, warning that if he was not taken into custody immediately, the United States would “render” him or pressure the Pakistani government to arrest him. [Link]

The same article also supports the idea that the plot was substantial, saying that they had experimented with a bomb in Pakistan:

Monitoring of Rauf, in particular, apparently played a critical role, revealing that the plotters had tested the explosive liquid mixture they planned to use at a location outside Britain. NBC News has previously reported that the explosive mixture was tested in Pakistan. The source said the suspects in Britain had obtained at least some of the materials for the explosive but had not yet actually prepared or mixed it. [Link]

And more on the technical difficulties inherent in mixing a TATP bomb mid-air:

Making a quantity of TATP sufficient to bring down an airplane is not quite as simple as ducking into the toilet and mixing two harmless liquids together… Don’t forget to bring several frozen gel-packs (preferably in a Styrofoam chiller deceptively marked “perishable foods”), a thermometer, a large beaker, a stirring rod, and a medicine dropper. You’re going to need them.

It’s best to fly first class and order Champagne. The bucket full of ice water, which the airline ought to supply, might possibly be adequate - especially if you have those cold gel-packs handy to supplement the ice, and the Styrofoam chiller handy for insulation - to get you through the cookery without starting a fire in the lavvie.

Once the plane is over the ocean, very discreetly bring all of your gear into the toilet. You might need to make several trips to avoid drawing attention. Once your kit is in place, put a beaker containing the peroxide / acetone mixture into the ice water bath (Champagne bucket), and start adding the acid, drop by drop, while stirring constantly. Watch the reaction temperature carefully. The mixture will heat, and if it gets too hot, you’ll end up with a weak explosive. In fact, if it gets really hot, you’ll get a premature explosion possibly sufficient to kill you, but probably no one else.

After a few hours - assuming, by some miracle, that the fumes haven’t overcome you or alerted passengers or the flight crew to your activities - you’ll have a quantity of TATP with which to carry out your mission. Now all you need to do is dry it for an hour or two.

The genius of this scheme is that TATP is relatively easy to detonate. But you must make enough of it to crash the plane, and you must make it with care to assure potency. One needs quality stuff to commit “mass murder on an unimaginable scale,” as Deputy Police Commissioner Paul Stephenson put it. While it’s true that a slapdash concoction will explode, it’s unlikely to do more than blow out a few windows. At best, an infidel or two might be killed by the blast, and one or two others by flying debris as the cabin suddenly depressurizes, but that’s about all you’re likely to manage under the most favorable conditions possible. [Link]