The B-2 Spirit must be a standoff-capable platform as well as a penetrating bomber to meet the emerging threats of the next few decades, the general in charge of the Air Force's nuclear operations said today. The B-2 "is going to increasingly find itself" in more difficult environments, Maj. Gen. C. Donald Alston, Air Force assistant chief of staff for strategic deterrence and nuclear integration, said during an Air Force Association-sponsored breakfast briefing. "When is that? Is it 2020? I...