He agonized for months before making his decision. As far as he was concerned, he already had the best job in the world: CEO of Goldman Sachs, the most revered institution on Wall Street. As its chief executive, Paulson traveled around the world, focusing much of his attention on China, where he had become something of an unofficial U.S. Ambassador of Capitalism, arguably forging deeper relationships with Chinese leaders than had anyone in Washington, including the secretary of State, Condoleezza Rice.