Looking back through some old entries, I came across this one: Al Qaeda Threatens Europe. from July 1. Almost 3 months later, the threatened 9/11-caliber attacks haven't taken place.
About the same time, some liberal mags were speculating that al Qaeda's capacity to carry out spectacular acts of terrorism has been so greatly diminished that the Bush administration is being disingenuous by even mentioning the terrorism threat as a real risk.
Of course, the liberals had no factual basis: they were simply trying to help Kerry. But they may have been wiser than they knew. There's a possibility that al Qaeda is in a position of Assured Mutual Destruction. American intelligence may be rich enough that al Qaeda cannot pull off a major--meaning thousands killed--terrorist attack without exposing its highest leaders. Like a nuclear ballistic missile submarine, which is invulnerable until it launches its missiles and gives away its position, bin Laden's position may be such that he cannot order a major hit without giving away his spider hole.
I don't think we've completely destroy bin Laden's ability to order such an attack. Then again, there's the problem of the dog that isn't barking. If he has the capacity and isn't using it, there must be a reason.
If I'm right, he will order the attack only when he's certain we have found him, making his capture a Pyrrhic victory.