Defense Secretary Donald Rumsfeld's delay of a decision on whether to procure Boeing KC-767 refueling tankers for the Air Force could lead to a new competition for the aircraft, a Defense Department official said today. The Pentagon said yesterday that the decision would be delayed until at least November, which will allow department officials to consider the results of two separate, ongoing studies on tanker requirements. Rumsfeld's decision was driven in part by a Defense Science Board study finished earlier...