On the occasion of Barack Obama's acceptance of the honor, it is worth looking back to a little history. Theodore Roosevelt, the first sitting President awarded the Nobel Peace Prize, did not attend the ceremony, but sent a telegram. But TR gave a Nobel lecture in 1910 - two years after leaving office, four years after winning the prize for mediating the end of the Russo-Japanese War, and four years before the world was plunged into The Great War - and his observations on peace are worth recalling, even as he was (at the time) optimistic about the possibilities for then-nascent international institutions:

In any community of any size the authority of the courts rests upon actual or potential force: on the existence of a police, or on the knowledge that the able-bodied men of the country are both ready and willing to see that the decrees of judicial and legislative bodies are put into effect. In new and wild communities where there is violence, an honest man must protect himself; and until other means of securing his safety are devised, it is both foolish and wicked to persuade him to surrender his arms while the men who are dangerous to the community retain theirs. He should not renounce the right to protect himself by his own efforts until the community is so organized that it can effectively relieve the individual of the duty of putting down violence. So it is with nations. Each nation must keep well prepared to defend itself until the establishment of some form of international police power, competent and willing to prevent violence as between nations. As things are now, such power to command peace throughout the world could best be assured by some combination between those great nations which sincerely desire peace and have no thought themselves of committing aggressions.

And so it is today; sometimes those combinations act through international institutions like the UN, sometimes they don't - and the day is not on the horizon when we could trust such institutions with police powers of their own. Those of us who love peace, therefore, must continue to heed Roosevelt's caution at how it is maintained.