He always was and always will. He's been the least war-hungry president in US history, by very far.
Because war is objectively bad and all. 
In the context of the Nobel Peace Prize, it (almost) always is. It's certainly never an actively good thing.
I think the Nobel Peace Prize is something that has long meant different things to different people. Is it a reward for a specific event or for the sum contributions of a lifetime? Theodore Roosevelt is easily one of the top three or so hawkish presidents we've had and did some horrible stuff, but is a Nobel Laureate for the specific accomplishment of negotiating peace between Russia and Japan. Is this view (very early on and probably closer to the original point of the award) that the award is meant as a reward for a specific accomplishment wrong? If it isn't wrong, then awards like Arafat's or Kissinger's start seeming far less absurd.
