At the height of the 2012 election campaign in late October, a U.S. delegation tiptoed into Japan and then China with scant media coverage. It was “unofficial,” but Hillary Clinton gave it her blessing. And it was headed by two figures high in the imperial firmament, Richard L. Armitage, who served as Deputy Secretary of State for George W. Bush; and Joseph S. Nye Jr., a former Pentagon and intelligence official in the Clinton administration and Dean Emeritus of Harvard’s Kennedy School of Government.