The British general who will soon take charge of troops in southern Afghanistan has said that British and other NATO forces in the area do not have time on their side. Major General Nick Carter, who will take charge of 45,000 troops in six weeks, said there was an opportunity to make a difference in the next year. But he said without the luxury of time, forces needed to show positive trends as quickly as possible. His comments come a day after the new head of the British army said defeat for allied forces in Afghanistan would have an intoxicating impact on extremists around the world.