I am not exactly sure how to answer this question so I will just be honest. I am an Obama supporter. I was very happy to hear of his achievement. I don't know what all this Nobel Peace Prize stuff entails, however, I am sure the country who gives it know. Evidently, he fit the profile for them to award him this honor.
Now, I assume he won the award because of the last eight years of war. . . and when Obama first took office, he has mended relationships with other countries, trying to stop the war, and even during that summit when the Chinese and French president was about to fight, Obama stepped in the middle and calmed them down. It was further said that he had a talk with each of them which in turn caused them to try to be civil. He has taken steps to spread PEACE which is what I assume is what the Nobel Peace Prize is about.