It is not that the Taliban ever worry too much about 'collateral damage'. Whatever their vow to avenge these 'martyrs', they've made plenty of their own. But this latest event looks like the kind of thing that will drive a permanent wedge between Nato and her allies in Afghanistan, and make the people there understand that, whatever the issues, the occupation cannot resolve them.
One of the reasons for the continuing occupation is that it is easier, from a political point of view, to stay, than to pull out - or 'cut and run' as it would be called, would make it seem that all the blood and treasure was spent in vain. So, in order to maintain face, the troops will stay on, searching for an opportunity to march out heads held high, rather than scrambling onto the Saigon chopper. Such an exit has almost invariably eluded Afghanistan's would-be conquerors, but I guess there's always a first time.