I think what is clear is that years of work trying to stabilise Afghan villages, billions of dollars spent training the Afghan military, is all being critically undermined by the actions of a few rogue soldiers.
Remember, the polls here show that 60% of Americans regard this war as not being worthwhile, that number is now certain to grow over the coming weeks.
The question is can the timetable be brought forward from 2014, perhaps to 2013?
I think the answer is it is increasingly likely and I think the political and military chereography of an accelerated withdrawal will be a central part of the conversation between David Cameron and the President at the White House over the next 48 hours.
The international military strategy in Afghanistan must not be derailed by the massacre of civilians by a US solider, leaders said.
With popular support for the war in Afghanistan fading, President Obama will be hoping for a quiet close to combat operations in 2014.
At least 16 civilians, including nine children, have been killed in an apparent shooting spree by an American soldier in Afghanistan.