He kicked out the neoconservative faction, led by former Vice President Dick Cheney, that prefers armed confrontation to diplomacy—and the world applauded in relief, along with the majority of Americans. Whatever the new president may or may not have done since then, nobody beyond a minority of die-hards would wish the Cheney faction to return.
Stopping John McCain, a neoconservative belligerent, and his dangerously clueless sidekick, Sarah Palin, was a significant achievement—and a close call until the final week or so. That is what Obama did, along with millions of other Americans. It is not a mere aspiration or a hope or a pretty speech.
http://www.truthdig.com/report/item/20091014_a_nobel_for_defeating_cheneyism/