NATO's Secretary General Anders Fogh Rasmussen has announced that all foreign troops will leave Afghanistan by December unless President Hamid Karzai signs a security deal with the United States.<br /><br />The agreement would allow US troops to remain in Afghanistan, but they would be immune from prosecution.<br /><br />President Hamid Karzai has so far refused to sign it, but his successor is far more likely to.<br /><br />Al Jazeera's Bernard Smith reports from Kabul.
