Against this we stack the the keep calm and carry on response of multicultural Woolwich, the bravery of passers by, the immediate denunciation of the atrocity by ordinary Muslims, the local anger at EDL opportunism.
One part of the left has been (once again) banging on about "root causes", i.e. what we do, which is like saying the "root cause" of rape is short skirts. CND trotted out a lightweight version of the same stupidity, describing the vicious butchering of a man for wearing the wrong T-shirt as some kind of inevitable "consequence" of Tony Blair's war.
George Galloway took the opportunity to smear the Syrian resistance, likening its Islamist strain to that which manifested in Woolwich - ignoring the thousands killed by Assad, ignoring his own previous cheer-leading of al-Qaeda linked terrorism in Iraq, ignoring his own stirring of the embers of perceived Muslim grievance in "Muslim lands". (No doubt he will stir further tonight, when he appears on the Iranian terror state's propaganda outlet to pontificate about what happened.)
Left Unity responded to the terror by talking about the "real" terrorism, i.e. what the West is doing, which may or may not be true (in my view it isn't) but is beside the point when most ordinary people here are shocked and grieving for Drummer Lee Rigby - about as sensitive as telling someone whose mother is dying of cancer that the real killer is car crashes.
And then some of the lefties I follow on Twitter seemed a lot more bothered by the racism that came out in response to the killing than by the killing itself, talking about "this shitty country" when all the evidence points to a pretty shitty world, which may not be the worst reaction but troubled me somewhat. It is worth remembering those attacked and killed by racists for being Muslim. For example, Mohammed Saleem, 75, was killed in Birmingham on his way home from prayers at his local mosque, and the motive may have been racism. But we mustn't score those attacks off against this attack, out of masochistic self-indulgent self-hatred or in some obscene zero sum identity politics game.
Grieve for this brave soldier in Woolwich, grieve for Mohammed Saleem, grieve for those killed in Iraq, for those killed by drones and by Islamists in Pakistan, for those killed by Boko Haram in Nigeria, for the victims everywhere of preachers of hate and death.
To donate to Help for Heroes go here. To report or get help with an anti-Muslim hate crime go here.
James Bloodworth's response was very sensible, as always. I liked Little Richardjohn's complex response. Darryl writes from close to ground zero. Aloevera's response to Glenn Greenwald is very pertinent. And below the fold are some of the more pertinent Twitter responses: