Joseph S. Nye Jr., an influential figure in shaping American national security policy, who wrote seminal books on foreign affairs, held top jobs at Harvard and in government, and coined the term “soft power” — the idea that America’s global influence was more than its military might — died on Tuesday in Cambridge, Mass. He was 88. His death, in a hospital, was confirmed by his son Daniel. Sometimes considered the dean of American political science, Mr. Nye led the John F. Kennedy School of Government at Harvard and held senior jobs in the Carter and Clinton administrations. His thinking radiated far outside the Ivory Tower: He influenced diplomats and national security officials, and, as a soft-spoken, fatherly figure, he was a mentor to many who made careers in government. Read full obituary.