What Does a Nobel Do for U.S. Leaders?

The Nobel committee said it awarded the Peace Prize to President Obama for his “extraordinary efforts to strengthen international diplomacy and cooperation.” The surprising news drew mixed reactions around the world, with many applauding the choice and others saying the award seemed premature and based on intentions, not accomplishments.

What does the award mean for Mr. Obama? Will it help or hurt him in domestic politics and in international relations? What impact did the Peace Prize have on the standing of other American leaders who received it, starting with Theodore Roosevelt?