There was momentary disbelief across the globe as the announcement stunned people from Norway to the White House. But it is true. US President Barack Obama has won the 2009 Nobel Peace Prize.

In a bemusing decision on Friday, designed to encourage initiatives to reduce nuclear arms, ease tensions with the Muslim world and stress diplomacy and cooperation rather than unilateralism, the Norwegian Nobel Committee awarded the peace prize to Obama.

Nobel observers were shocked by the choice so early in Obama's presidency.