A National Security Agency program that listens in on international communications involving people in the United States is both vital to national security and permitted by the Constitution, a government lawyer told a judge here today in the first major court argument on the program. But, the lawyer went on, addressing Judge Anna Diggs Taylor of the Federal District Court, "the evidence we need to demonstrate to you that it lawful cannot be disclosed without that process itself causing grave harm to United States national security." The only solution to this impasse, the lawyer, Anthony J. Coppolino, said, was for...