But 'the clandestine contacts with the Taliban have borne little fruit, according to people who have been told about them. But they have helped undermine the remaining confidence between the United States and Mr Karzai, making the already messy endgame of the Afghan conflict even more volatile,' the duo report. 

And, finally, 'frustrated by Mr. Karzai's refusal to sign the security agreement, which would clear the way for American troops to stay on for training and counter-terrorism work after the end of the year, President Obama has summoned his top commanders to the White House on Tuesday to consider the future of the American mission in Afghanistan,' they say here.