One of the more interesting aspects of Ian Kershaw’s biography of Hitler, which will probably be the standard, if it is not already, is his treatment of how the Holocaust was an evolutionary process. It did not spring ex nihilo from Hitler’s forehead, all at once, but evolved gradually, from the anti-semitism that was a bedrock principle of the Nazi movement combined with and fueled by a built-in tendency towards radicalization in which Hitler and his most fanatic followers egged each other on incrementally to bloodier and greater atrocities.

I would lay odds that Al Qaeda worked and works in the same way, and I suspect all criminal enterprises headed by fanatics are similar. The Fanatic-in-Charge offers his acolytes a millenarian future, attainable but for the Other blocking the way — and the acolytes fall all over themselves piling up bodies to get to Nirvana. The Leader sees their efforts, indicates his pleasure and the cycle begins again.