The National Security Agency's senior civilian official will soon be leaving her post for an overseas billet, according to intelligence community sources. Barbara McNamara, deputy director of the Ft. Meade, MD-based signals intelligence agency since October 1997, will become NSA's senior U.S. liaison officer in the United Kingdom. The job is considered a plum assignment and involves serving as the U.S. SIGINT community's principal interface with Government Communications Headquarters, which is Britain's NSA equivalent. The GCHQ liaison post is currently...