Daniel Pipes coined the phrase "Sudden Jihad Syndrome"; Hugh Hewitt identifies five deadly post-9/11 cases in the US with similiar anti-Semitic symptoms and writes that "transmission is easy, and the appearance of the violent derangement that anti-Semitic Islamist extremism produces is both sudden and deadly":

None of these five incidents is the sort of terrorist attack that we are most concerned about --the meticulously planned, coordinated attempt to cause spectacular devastation and casualties in the hundreds if not thousands. The London airlines bombing plot, like the London Tube attack, the Madrid rail attack, Bali resort bombing, and the Beslan school massacre are examples of this sort of terrorist atatck, and they rightly receive the bulk of Homeland Security's attention and analysis.

But isolated, single terrorist attacks are of great concern, and not just because of their real victims, but because of what they tell us about the spread of the hatred, and its potential to spread farther and faster than we ever dreamed.

It seems possible that we are close to a tipping point where so much anti-Semitic propaganda has been pumped into the world via new technologies and emboldened regimes and charismatic fanatics like Osama, Nasrallah and Ahmadinejad that the madness we would hope was confined to caves in Afghanistan and poor madrassas of Pakistan has in fact traveled far and at a furious pace, deep into France, now deep into London, and now we have to worry, deep into the United States.

It does not have to spread widely in American Muslim circles to provoke terrible violence by a few. There is no evidence of anything like the scale of Islamist hatred that consumes parts of France appearing in the U.S., but neither is it impossible that it will arrive here. What the five examples above underscore is that a segment of the Muslim population is susceptible to the deranging effects of anti-Western screeds from radical imams. That segment might be limited to the already deranged --the driver/killer in San Francisco and the shooter/killer in Seattle are both said to suffer from mental instability.

But the point is the segment exists, and individuals within it have killed.

What, exactly, triggered their violence?