Seymour M. Hersh, a former correspondent for The New York Times, won the Pulitzer Prize for international reporting in 1970, for his revelation of the massacre at My Lai, in South Vietnam. He is the winner of virtually every major journalism award, including the George Polk Award, which he has received four timesmore than any other reporter in the history of the Polk Awards. His new book, which will be published early next year by Summit, is a history of Henry Kissinger's service as national security adviser to Richard Nixon, during Nixon's first term. The article below is drawn from that book; it deals with White House wiretapping activities and with the White House internal-security unit known as the Plumbers. A second Atlantic article by Mr. Hersh, to be published later this year, will be concerned with one aspect of the Nixon-Kissinger foreign policy during Nixon's first term.