A senior administration official yesterday said "there are probably hundreds" of strategic targets such as command and control centers and weapons of mass destruction stockpiles that the United States cannot destroy because they are housed in hardened or deeply buried facilities. Worldwide, there are probably thousands of "strategic targets" at hardened or buried locations, said John Gordon, chief of the Energy Department's National Nuclear Security Administration. Conventional weapons can defeat "the large majority" of those targets, he said, but hundreds...