President Barack Obama accepted the Nobel Peace Prize in Oslo by conceding that others were more deserving and then mounting a passionate defence of "just wars" such as the conflict in Afghanistan.
"We must begin by acknowledging the hard truth that we will not eradicate violent conflict in our lifetimes," Mr Obama said in a speech that was notable for his uncharacteristically muscular rhetoric and unapologetic tone.
"There will be times when nations – acting individually or in concert – will find the use of force not only necessary but morally justified."He even suggested that "war is at some level an expression of human feelings".