That we’ve misunderstood the beheadings. Some snippets:
This is not about us — it is about them. The beheading films are recruitment tools. They've been around for a long time, part and parcel of the first generation of "jihad" home movies, circulated mostly in North Africa to excite homicidal fanatics and lure them into the Islamist bands. The main difference between then and now is that their marketing and distribution have improved, thanks to their comrades at al Jazeera and al Arabiya, and the Internet.
...
We cannot wage an effective war unless we understand the nature of our enemy. If we do not grasp that the terrorists' ranks are full of people who are there precisely because they are thrilled by the prospect of beheading human beings, we will fail to see the war through to its necessary conclusion. The beheadings are about them, not us. They show us very important things we need to know: What they are, what they want, what they will do if we do not stop them.
Read the whole thing!