“Almost great” is George Packer’s measured judgment on the life and character of the American diplomat Richard Holbrooke, who was trying to broker an end to the war in Afghanistan when he died suddenly in 2010. Holbrooke left the war pretty much as he found it, and peace is no closer now, nearly a decade later, but that isn’t what explains the cruel precision of Packer’s judgment. It’s the man. Holbrooke had the serious intent, the energy, the friends, the wit, and even the luck needed to accomplish great things, but he fell short. Packer circles the question of why in his new biography, Our Man: Richard Holbrooke and the End of the American Century, but the force of the man survives the interrogation.