America, on the president's orders, has intervened militarily in Libya; the president has given a speech explaining the intervention and the manner of it; the country and the world debate the matter as events unfold; the outcome remains uncertain.  In his speech, the president insisted that, because the Libyan people faced "the prospect of violence on a horrific scale," America had a responsibility to act. "To brush aside...our responsibilities to our fellow human beings under such circumstances would have been a betrayal of who we are." 

These letters are particularly concerned with "who we are" as a people and what this requires of our politics, domestic and foreign. So I leave aside for now the many other interesting and important questions swirling around the president's words and deeds, including his deference to the United Nations and his neglect of the United States Congress.