Surely the end of British and Nato operations in Afghanistan must now be sight.
Defence Secretary Philip Hammond tells us that the immediate cessation of joint Nato-Afghan army patrols is not a change of strategy, but that is clearly what it is and it is the Afghans that have brought it about.
It has been obvious for some time that Western strategy has failed. However the rapid increase in "green on blue attacks" means that the comforting myth of hearts and minds being won, and the creation of a participatory democracy, can no longer be maintained.
Of course Nato, in public at least, is still trying to convince us that there is no discernable pattern to these attacks and that they constitute a very small threat.
But given that guards are now mounted to protect our troops from their Afghan comrades while they sleep, and that Americans carry loaded weapons even when off duty, it suggests an acknowledgement somewhere that Nato is a deeply unwelcome presence.
This is not surprising.
After 12 years and billions of pounds of aid, we prop up an Afghan government so functionally useless that, as US President Barack Obama recently conceded, even within Kabul "it is wholly undermined by corruption and has difficulty delivering even basic services to its people."
The leaked Afghan war logs show that Nato has also killed a large number of civilians.
Jingoistic Westerners may only dimly remember such "regrettable" incidents as the strafing of a children's bus by the French in 2008, but we can be sure that these events live fresh in the minds of the Afghans - and why not?
Even by Nato's constantly shifting standards, the whole enterprise been an expensive and unmitigated failure.
It's all over. The withdrawal of troops is long overdue.