Pakistan and Afghanistan have long had vaguely defined borders, and the new interest in controlling illegal border crossings by Taliban and al Qaeda, has put the spotlight on the need to actually define the border. Exactly where the border was, except as the places where border posts were placed (along roads), never caused any problems. The tribesmen in the hills wandered back and forth without any thought for where the border was. But now it is important, especially since Afghan and American troops are chasing Taliban fighters right up to the border, and sometimes across it.