Part of the reason that tracking down terrorists is hard is that they sometimes hide in mountainous, tribal-dominated regions of countries like Pakistan -- which appears to be where bin Laden has been hiding out since the fall of Afghanistan. The problem is that it's rather difficult to send a massive U.S. force (which is what would likely be required) into this region since it would probably cause the Pakistani government to fall and be replaced by a much more radical Islamic regime. Did I mention that Pakistan has nuclear weapons?

Since Al Qaeda was apparently silly enough to take some potshots at Musharraf, he's felt free to send some troops into the neighborhood to roust out the baddies lately. Not entirely effectively yet, but it's progress. Whether the Iraq war had anything to do with encouraging Musharraf to do so is unknowable at this time.