AP Photo

A week after being elected President, Barack Obama summoned Richard Holbrooke to his transition headquarters, at the Hilton Hotel in Chicago. To some members of Obama’s staff, the invitation was surprising: Obama and Holbrooke hardly knew each other, and Holbrooke had firmly supported Hillary Clinton during the primaries. Although Holbrooke, a State Department veteran, had been careful not to disparage Obama, the President-elect’s advisers saw him as a problematic, if rare, talent. Holbrooke had a reputation for creating drama—speaking ill of rivals in government, hotly pursuing the press—and it was not clear that he could play unselfishly on the fanatically disciplined Obama team. In June, 2008, after Clinton dropped out of the race, Holbrooke began working his connections to...