Ground troops are expected to go into Afghanistan sooner rather than later if the Taliban fail to take advantage of the pause in bombing to hand over Osama bin Laden, senior defence sources said Friday. Geoff Hoon, the Defence Secretary, admitted that the imminent onset of winter meant that time was running out. He said: "Everyone knows that the weather in a few weeks' time in Afghanistan will be particularly difficult." But small-scale insertions of special forces - such as the SAS and its American equivalent, Delta Force - for reconnaissance purposes are unlikely to be affected by the winter, and it may even help them.