Pure luck!

Now we know that the absence of a major terrorist disaster in the USA is due to pure luck. The "shoe bomber" Richard Reid was detected and brought down by fellow passengers, as was the "underwear bomber" Abdul Muttalib. The billions of dollars spent on the intelligence agencies, the Home Security Agency, the FBI, the CIA and others did not detect or prevent these terrorist attempts.
In the latest case, the planners were clever, first they used a Nigerian Muslim; many people don't realize that the northern half of Nigeria is Muslim and that there are often serious conflicts between them and the Christian south. This is the first time that a Nigerian Muslim has been used as a suicide bomber.
Second they used a non-electrical bomb, purely chemical, with a powder sown into the underwear and a syringe of liquid to be added to it during the flight. This made it much more difficult to detect by standard X-ray means. Fortunately, the amount of heat produced by mixing the chemicals not only caused a small fire and burnt the perpetrator, but also melted the device thus preventing further mixing and an explosion. Third, the bomber embarked in Amsterdam, an unusual entry point, and Schipol airport is supposed to have excellent security measures.
This example shows once again that the oft-repeated mantra that suicide bombers are "poor and desperate" is completely wrong, Muttalib like many of the previous ones comes from a wealthy background and is techncially qualified, he was an engineering student in London. This is also the profile of Osama bin Laden himself.
What went wrong? Well apparently the 20 mins the bomber spent in the toilet must have been for preparing the device to inject the liquid from the syringe, and maybe to say his last prayers. The apparent fault in the device was that the liquid failed to mix sufficiently with the powder and hence to explode, it only mixed with a small amount at the point of entry and this produced enough heat to ignite but not to explode. Once again saved by luck!
Pres. Obama has admitted that this was a significant intelligence failure, given the information on this young man (his visit to Yemen, his father's warning, his exclusion from the UK, his name on a warning list), the ideal that the intelligence agencies share information is a myth. Also, the lack of judgement is clear. They don't take the threat seriously enough, it's not their lives at stake.
The perpetrators won't use the same plan again, they will come up with something new and clever. After the use of the planes themselves as bombs, they tried shoe bombs, they tried to use liquid bombs and that was prevented in the UK, and now underwear bombs. What next? In order to prevent further clever bomb plots, our best minds should be trying to find ways to prevent that. The best way is to have a full body X-ray and a chemical detection device at each airport as well as serious profiling. You step into a booth or two and each does a quick scan, you answer a few questions, and if you are not a young Muslim with a record, you're on your way. Good luck!