A nation riven by factions, in which the minority has no hope of ever becoming a majority, or in which some group knows it is perpetually outcast, will seem oppressive to its members, whatever the legal pretensions.

Every civilization that has ever existed has ultimately collapsed. History is a tale of efforts that failed, or aspirations that weren’t realized. So, as a historian, one has to live with a sense of the inevitability of tragedy.

I would say the special experience of American wartime policy in the last 40 years, from Vietnam on, is that the war itself became controversial in the country and that the most important thing we need in the current situation is, whatever disagreements there may be on tactics, that the legitimacy of the war itself does not become a subject of controversy. We have to start with the assumption, obviously, that whatever administration is conducting a war wants to end it.

A bluff taken seriously is more useful than a serious threat interpreted as a bluff.

Most high officials leave office with the perceptions and insights with which they entered.

Access to natural resources can become a question of survival for many states.

If the six-nation forums dealing with Iran and North Korea suffer comparable failures, the consequence will be a world of unchecked proliferation, not controlled by either governing principles or functioning institutions. A modern, strong, peaceful Iran could become a pillar of stability and progress in the region. This cannot happen unless Iran's leaders decide whether they are representing a cause or a nation - whether their basic motivation is crusading or international cooperation. The goal of the diplomacy of the Six should be to oblige Iran to confront this choice.