Mehsud, or the Dangers of No. 2
Whether or not he's actually dead, Hakimullah Mehsud illustrates one of the dangers of a CT strategy based on organizational decapitation -- namely, that the No. 2 guy waiting in the wings might actually prove to be more dangerous than the guy whose charred boots he filled. A similar phenomenon has been noticeable among the Basque ETA terrorist group, which has replenished its ranks with what appears to be an even more militant younger generation. (Of course, Americans need only look to their own very recent past for another useful illustration.)
I have admittedly been among those who have made light of the endlessly recurring "death of AQI's no. 2" stories we've seen over the past few years. But it might actually make more sense to go repeatedly after no. 2, while leaving the top dog alone. Clearly, there are advantages to destabilizing and degrading the enemy's leadership, especially if it leads to power struggles and weakens organizational cohesiveness. But it comes with risks. And there are also advantages in continuity of enemy leadership, which allows for a corresponding continuity in our own ability to predict its operations.