Among the most vicious enemies of human welfare is poverty. In a world plagued with limited resources, bad governments and unsound economic policies, it often appears to be an inescapable scourge. Most people paid no attention in 2000 when the United Nations proclaimed the goal of halving the number of earth's inhabitants living in extreme poverty by 2015, compared to 1990. But way ahead of schedule, writes Steve Chapman, the target has already been hit. We have capitalism to thank for that.