If it is a random 25% or so, that might be sufficient deterrence. say, you plan an attack. Would you run a 75% chance of it being thwarted before you enter the plane, or do you start looking elsewhere?
I read on here the other day from someone who studied Al-Qaida and was a part of the terrorist watch group with the FBI that when they plan something it has to be 100% that the plan will work before they attempt it. He was saying they wouldn't dare risk it even if it was a 75% risk. Which is interesting. Just thought i'd throw that in here.
Al Qaida (and similar groups) want to be seen as always successful. If there's regular news about their plots failing, their backers quit backing them and move on to a group that fails less.
Capable staff is perhaps the largest challenge facing terrorist organizations. If Al Qaeda could have sent four people with shoe bombs or underwear bombs, you'd better believe they would have. And if explosives were the limiting factor, that would mean Richard Reid and Umar Abdulmutallab were the most capable of agents on hand. And that simply doesn't paint a picture that suggests they have a very large pool of capable, dedicated terrorists to work with.
Despite what the fear-merchants would have us believe, all indications are that there simply aren't that many intelligent, capable people who are willing to give their own lives to lash out at Western civilians.
