The Obama administration is scurrying to implement new procedures to find and keep potential terrorists off U.S.-bound planes, as results of a preliminary intelligence review flow into the White House. Emerging as a central focus are deficiencies in the U.S.'s network of watch lists, a system designed after the Sept. 11 attacks to keep tabs on potential terrorists and prevent them from boarding planes, according to a senior U.S. counterterrorism official. The official noted that government audits turned up problems in recent years, including gaps that kept suspected terrorists from being added to the U.S.'s no-fly list. President Barack Obama...