It has also forced us to confront the idea of words as weapons, and the relationship between ideas and actions, in a world of conscienceless criminal violence that operates without employing any code or precedent of its own.
To phrase the essence of the problem shortly, you are perhaps more likely, as a reader of this column, to be blown up at work or play, or on the way to work or play, by a "homegrown" or "lone wolf" or "self-starter" fanatic using whatever explosive or incendiary tools may lie at hand, than you are to die at the hands of al-Qa'ida or al-Shabab or any of their shifting surrogates.
In the same way, it is at least as likely that a local operative will emerge from the American suburbs to commit one random and unpredictable act as it is that a fanatic will leave our shores and take himself to Somalia or Yemen or Afghanistan.
And so we have the figures of Major Nidal Malik Hasan, unsheathing his weapon at Fort Hood; or Faisal Shahzad, rigging his SUV to explode in Times Square; or Umar Farouk Abdulmutallab, stuffing his underwear with combustibles and (rather too easily, given his record) boarding a flight to Detroit.
It doesn't seem strictly accurate to use the "lone wolf" designation in all these cases, because a potent influence on the loner can be a homegrown counsellor or adviser, who speaks the vernacular and has also lived in "the belly of the beast".
In the recent past, Awlaki has been the classic and most successful instance. His evolving contact with Hasan, walking him through all the stages that lead up to the granting of religious permission to shoot at will, was quite systematic. There were times when Awlaki was working under our very noses, propagandising in Virginia and elsewhere from the context of an existing mosque.
But he had not, at that stage, fully pupated himself into a committed Salafi jihadist. So now we have the phenomenon of an American citizen, able to whisper directly into the ears of people living here, but until recently being able to do so from a geographical location where our laws cannot reach him. There is no precedent, however remote, for a legal and moral challenge of this kind, let alone for a political or military one.
Since this dilemma will be with us for some time, may I recommend a recent booklet that offers the most background to the emergence of this fascinating and frustrating enemy? Called As American as Apple Pie: How Anwar al-Awlaki Became the Face of Western Jihad, the booklet explores the tradition of English-speaking Salafi agitators working in the West, a tradition that is longer and more ramified than many people think. But I find myself more absorbed by the aspect represented by the late Samir Khan, a Pakistani-American who until he died in the same Hellfire attack was the editor of al-Qa'ida in the Arab Peninsula's online magazine Inspire. While other martyrdom tactics were being used on faraway battlefields, Khan said not long ago, and even while Osama bin Laden was being removed from the chessboard, the idea of homegrown attacks on US soil was moving "into fifth gear".
In a rhetorical way, this mirrors bin Laden's obsessive distinction between operations against India, say, or Iraq, and spectacular assaults on "the far enemy", or the prestige and security of the US. To his last days, he argued for a renewal of the second type of warfare. It also raises a much less grand image: that of the pathetic amateur and misfit who can commit perhaps one limited act of vicious spite against his neighbours or co-workers or even passers-by.
I think it is important to watch for symptoms of sheer degeneracy like picknose wannabe murderers lurking in their parents' basements because there is evidence that such things (like the use of small children to carry suicide bombs) arouse revulsion even among those who otherwise wish us ill.
It also dramatically reduces the calibre of recruit. On the other hand, and too little remarked, such tactics do something that is worth the price of a good deal of high explosive. They annihilate trust and confidence. Do you really want, next to you at boot camp, a man who prostrates himself five times a day? Should one say anything about the man with the beard in the next seat?
Slow and sidelong cultural erosions of this kind can do incalculable harm. And they can also be horribly and cheaply self-replicating: some people will "overreact" to a spectre of Islamism, however slight, and this will offend the man who is only trying to meet his prayer obligations, and then a whole machinery of supposed grievance and redress clanks into action. Meanwhile, those who orchestrate this little carnival of mayhem and social corrosion are able to do so from areas that are beyond our legal jurisdiction but within our military reach, and to taunt us while doing so.
As we engage with the horrible idea that our government claims the right to add its own citizens to a death list that is compiled by methods and standards unknown, we must concede that no government on earth faces such a temptation to invoke what I suppose we could call a doctrine of pre-emptive self-defence. Those who share my alarm at the prospect of this, and of the ways in which it could be abused, are under a heavy obligation to say what they would do instead.
Christopher Hitchens is a columnist for Vanity Fair and Slate Magazine. He is the Roger S. Mertz media fellow at the Hoover Institution at Stanford University
