More than half of the Quadrennial Defense Review follow-on study efforts directed by the Pentagon earlier this year focus on dealing with "disruptive" technologies and innovations that could diminish the Pentagon's high-tech edge against future adversaries, according to a senior Pentagon official. This concentration reflects a concerted effort to deal with a challenge the Pentagon highlighted last year in its National Defense Strategy -- along with irregular and catastrophic challenges -- as an area in which the military must boost...